White screen.

I am having trouble accessing Duolingo itself (the skill trees), but not the stories or the discuss part (obviously). What should I try?

February 3, 2020


What browser and version do you use?

I have just sent in a bug report for a JavaScript problem for Mozilla Firefox V52.9.0esr a few minutes ago.

Bug Reference code: 1762983

I use Google.

Google Chrome? What version?

I'm pretty sure I don't have chrome.

Internal Google browser on Android OS?

So what is your device, Android operating system version and version of the (internal) browser app?

Can you open a web console and check for JavaScript errors?

I use a regular desktop computer.

Quote: pIwo4arh


I always like to learn about new (available) software and technology even I can't directly use it on my older hardware.

But now you made me curious.

Obviously you are using:

  • a computer
  • in desktop mode
  • and a Google software product
  • but not the "Google Chrome" browser.

Sorry for asking, but what other "Google browser software" is left you could be using?

I would have known about the availibility of e.g. a Chromebook with Chrome OS, but right now I have no clue what software you might have installed on your system (computer).

The user Anitramwaju confirmed that Chrome version 67.0.3396.87 does not work anymore (this was known):

Thank you for your input and my problem is now resolved.

I have the same problem with Chrome version 67.0.3396.87 on OS X (the last version I can install on my OS version).



thanks for your feedback.

We had several MacOs Troubleshooting threads in the last few months:

Quote: I have the same problem with Chrome version 67.0.3396.87 on OS X (the last version I can install on my OS version).

I am a bit surprised that you only run now into this issue.

Is there a web console on your Chrome software (on Mac OS X) so you could report the JavaScript error message and copy the detail Stacktrace?

According to the old "No access to Home" thread we had to install at least Google Chrome version V77 on an older Android tablet
(Android OS 4.4.2 still allows to install newer software versions from both vendors; only Android OS 4.2 is restricted not getting further browser vendor updates).

And only newer Mac OS versions are supported by the Google and Mozilla vendors for more recent browser versions.


A friend of mine had an older Firefox and Chrome version installed (maybe V6x or V5x) on the hardly used tablet and only an empty page was rendered.
The update to Google Chrome V77 solved this last year.
I did not bother trying to find out about any potential error messages in the "browser web console" as I quickly wanted to save my streak when I visited him.

Sounds like you're on the same OS X version as me, try installing the latest Firefox as that works on my system.

Please can you explain me the problem in understandable words? What is the problem now exactly? Why can i not use Edge like before?



Quote: Please can you explain me the problem in understandable words?

I explained it in more detail in my (quite long) bug report to Duolingo staff/developers from a technical side including JavaScript stacktraces.

Theoretically, I think this should be enough that they can fix their web frontend code or make it at least compatible with all browsers and multiple versions (if they care).

Quote: What is the problem now exactly?

Staff/admins rolled out a new code update on Monday 03. February 2020 requiring newer Javascript APIs in a browser.

It probably is only compatible with Google Chrome V79 and latest versions of Mozilla Firefox Quantum V71-72....I am highly guessing at this stage as I need to test it myself.

But as you can see other users have success installing the very latest versions of Chrome (or maybe Firefox).

Quote: Why can i not use Edge like before?

Well, I have the same issue (for Firefox) on my older system.

Because it does not have the same JavaScript API - like my old Firefox V52.9.0esr browser - which the new web code update requires.

Their code tries to call a specific JS function and the error message is this:

Thank you for your answer.


Quote: Why can I not use Edge like before?

According to this table Microsoft Edge V79 should support this Javascript function.

Have you tried it already?

V79 refers to Microsoft's new Chromium based Browser. As it was only released to the general public a couple of weeks ago, most Edge users are still on Edge Legacy.

Microsoft has released a new version of Edge that should be compatible with these changes (The new version has been in development for months, it wasn't released because of Duolingo's changes).

Most people will get the new version of Microsoft Edge automatically over the coming months, but if you want, you can get the new version immediately from

(I can't find any information on whether this will work with Windows 10 in S Mode).

So, Edge will update automatically eventually?

Microsoft has announced that the rollout will be phased over the next several months, and the plan is that everyone will be upgraded to the new browser automatically. You can "jump the queue" by downloading and installing the new version manually.

Note that the new version of Microsoft Edge is also available for WIndows 7 and for Mac OS, as well as Android and IOS (you can share the same bookmarks on desktop and phone, for example).

I see. Thank you very much!

Thank you so much, I understood the problem from the other comments but didn't know how to fix it. I am not technical, and was bemused and resigned to losing my streak until I read this. I followed the link you gave and installed the new version of edge and was in!

Well done, I'm pleased for you and thanks for sharing your solution.

Saving your streak

Stories are still working for me (on Firefox V52.9.0esr) without JavaScript errors.

Use them to gain a few XPs (22-24XP+) and save your streak for today.

Yep, I've now got the blank page as well! Luckilly it's working okay in Firefox, but Chrome is toast it seems.

Mac OS X 10.9.5, Chrome Version 67.0.3396.87 (Official Build) (64-bit)

Really hate it when websites start forcing you to update software! : (

I am having the same problem everything works except the tree and I am not in firefox i am in seamonkey

I've got the newest firefox and it works fine. Just finished a lesson.



Quote: I've got the newest Firefox

This is then V72 I guess?

Too bad, the other computer system on another floor got replaced and I currently have no chance to rest with previously installed FF V68esr, V69-70 browser versions that easily.

There had been so many other Troubleshooting posts in the last weeks from multiple users (starting December/January) that I actually created a poll three weeks ago if the latest / most recent versions of Chrome V79 or Firefox V71-72 could theoretically be the issue:

And now there was made another web update on 03. February 2020 which makes it even worse (for me and several other users).

the problem with my computer is that I can't download another browser as hp says that they aren't 'okayed' by the app store :(

you can opt out of the " app store approved apps only". I think you can do that in the app store itself.

I am using Microsoft Edge and only get a white screen on Learn. I can however access stories. Apparently, the only way to keep my streak alive for now. Please help.


Quote: I am using Microsoft Edge and only get a white screen on Learn

According to this table Microsoft Edge V79 should support this Javascript function.

Your advice is simply genius! I installed the latest version of Microsoft Edge & everything is working and looks great. Thank You for your time and worthy advice.

Please edit your subject, otherwise this thread is getting quickly downvoted.

I don't know what else to say.

change the title to something descriptive and precise

That is what I know... this discussion is what I wanted.

Ok, I upgraded my chrome browers, it works there now . I upgraded my Mozilla Firefox Browser and it works there too. Seamonkey is next. Good luck


What versions are installed?

Chrome V79 and Firefox V71/72?

Chrome 8.03087.87 and firefox 72.0.2 (64x) and seamomkey 2.49.1

I always used edge


Quote: I always used Edge

According to this table Microsoft Edge V79 should support this Javascript function.

Most users of Windows 10 will still be using the Legacy version of Microsoft Edge (Microsoft Edge 44.xxxxxx), unless they have manually downloaded and installed the new Chromium based Edge from - just checking for updates won't get that new version for most users (yet - it's a staggered rollout, so some users have gotten the new version through the normal update process).

Hello all,

when I try to debug into the application:
In the current app-d12d541d.js file which was rolled out yesterday I found this code line:


r.uniq(r.compact(t).map((function(e){return e.split(" ")})).flat()).sort().join(...)....


Map and split functions probably gives back an Array or something like this?!

According to Mozilla documentation, the flat() function has only been implemented for LATER browser versions, see this table:

Scroll down to Browser compatibility:

  • Firefox V52.9.0esr obviously is missing it
  • Microsoft Edge does not support it (might change with Chromium based later versions??)
  • Safari only seem to support it for V12+
  • Google Chrome requires at least V69+ (V77 was fine last year)
  • Mozilla Firefox introduces it in their JavaScript engine with V62+ (so V68esr, 69-70 or V71-72 all should be fine??)
  • Opera requires V56 (and old WinXP or Vista downloads use a much older version)

Well, I am not that sure about this fact and the React library usage / code sample, but to me - as a non-Html/JS frontend developer - it sound a little bit plausible?!?


  • 1) So I am now searching for a proper way to locally patch the (downloaded) React library not to use the flat() function as we had it before all the time and overwrite some code of the library with other sample code.

  • 2) To rollback to a previous (better compatible) React version locally which does not make use of function calls which are not widely available in (older) browser Javascript engines.

  • 3) To provide a npm shim for the flat() function and dynamically inject it in the Duolingo web application code to overcome the legacy Javascript browser engine.

  • 4) Or to patch the browser internal JavaScript engine on my older Firefox V52.9.0esr version from the more recent Firefox V62+.

Is this somehow possible?

Can any lead / senior frontend developer give some advise how to workaround the situation if Duolingo staff may not rollback their web code change or can not patch their React library to be compatible with more (older) browsers?

Thomas, a million thanks for all your time and attention to this!

I installed (reluctantly!!) Firefox and now Duolingo lessons are working.

If I understand, you are a user also, and just happen to know very very much about computers and software. You have helped quite a lot of people access their lessons on Duolingo using the workarounds that were suggested in your posts.

Here is another nice table about what concrete browser versions (on what platforms) support the Javascript Array flat() function:

@staff @developers

I continued searching for shims / polyfills and code suggestions on the Internet how to provide the flat() function manually by some code examples.

I feel a bit discouraged that despite having invested some time in the evening that I have not yet found easy / quick solutions how to patch this old Firefox V52.9.0esr browser once and for all or how to come up with a good Javascript bootstrap Array.prototype.flat() extension/overwrite solution preferably in Tampermonkey at the top of any website (like Duolingo).

I won't upgrade this older Laptop anymore and I definitely can't install any newer browser versions.

If someone of you has any ideas how to make use any of those above 1-4) workarounds and to permanently fix it and to make the built-in (limited) Firefox JavaScript engine better usable, I would be glad to hear your feedback.

Looks like that more and more 3rd party Javascript (UI) libraries or websites might require newer JavaScript API function implementations (newer specs) which simply are not available in Firefox V52.9.0esr.


Tech stuff goes waaaaay over my head, but I keep everything up to date on my computer (windows 10 laptop) and I have this problem too (I use Microsoft Edge.) I was able to get to other parts of Duolingo from emails linking to the forums here, but I can't access my skill tree and by extension, lessons. I tried reading the comments here, but as I said, it just goes over my head. Can someone explain in layman's terms what I have to do? Do I, perhaps, just wait this out and keep checking for updates via in-computer control panel?


Quote: Can someone explain in layman's terms what I have to do?


  • 1) Try to upgrade Edge to V79
  • 2) Or install Google Chrome (V77-78, or try with the latest V79 version)
  • 3) You can also try a recent version of Mozilla Firefox Quantum (most recent V71-72 or v69-70, V68esr)


According to this table Microsoft Edge V79 should support this Javascript function.

Is this true? Have you tried it already?

I am not exactly sure where the V79 version comes from....maybe as the new Edge is now based on Chronium?

Quote: Do I, perhaps, just wait this out and keep checking for updates via in-computer control panel?

The best would be if staff could patch their web code for other/older browsers.

If and when this happens: We do not have any idea, sorry. Mission completed.

2+ bug reports have been created today and linked in this thread.
May take a while to come up with a solution.


Maybe some frontend programmer god finds out how to inject our own compatible code for the "flat()" function into the Duolingo web application:

However, this will probably not happen within 24-48 hours!

Feel free to pick one of the three above suggestions so you can learn immediately again and hang onto this thread when there any news.

"1) Try to upgrade Edge to V79"

What exactly does this mean and how do I do it? Wouldn't this just mean getting normal windows updates?

"2) Or install Google Chrome (V77-78, or try with the latest V79 version)"

How is it possible to choose a specific version to download and where is a reliable source to do so from?

"3) You can also try a recent version of Mozilla Firefox Quantum (most recent V71-72 or v69-70, V68esr)"

Same questions as above. (Like I said, this kind of stuff goes waaaaay over my head. I have no idea what all these numbers and letters mean, except that I can guess that "v" stands for "version.")


"1) Try to upgrade Edge to V79"
What exactly does this mean and how do I do it?

You can simply download Edge (latest is 79.0.309.71 and will be automatically offered) here:

Quote: Wouldn't this just mean getting normal windows updates?

I do not use Win10, sorry.
I do not know if MS rolls out later Edge versions (like V79) over their Windows update service or not.

Normally every browser has an option somewhere in the menu / help / about menu to show the currently installed browser version.

Or you right click click on the edge .EXE file on on your C: or D: hardware and check the detailed version attributes.

Quote: "2) Or install Google Chrome (V77-78, or try with the latest V79 version)"
How is it possible to choose a specific version to download

Normally only the latest versions are offered.

Sometimes you can click for offline install files on a specific product link to show multiple platforms and sometimes you can also download older versions.

Quote: and where is a reliable source to do so from?

Install the (latest offered) version (V79) of Chrome here:

For Mozilla Firefox (V72.0.2) here:

There also is a "Advanced Install Options & Other Platforms" link at the bottom.

Just go with the Windows 64-bit file link (online installer).

Quote: I have no idea what all these numbers and letters mean, except that I can guess that "v" stands for "version.")

Yes, just the version number(s).

ESR means "extended service release" on Firefox but you are good to at least try the very latest version of 72.0.2 for the Duolingo website.

If it works or not you will find out later (after installation) :-)

Currently I have to pass on your question how to force a specific (older) Chrome or Firefox version...if they are nowhere directly linked on the vendor homepages or their (FTP) archive sites.

Maybe I will find out in the next couple of weeks / months as it was on my todo list to compare newer versions vs older browser versions for the compatibility with the Duolingo website and which one creates more headache.


Because too many people have reported audio/empty page errors over the past weeks in the Troubleshooting section which might (I am just guessing) be also related to January browser/vendor updates.

See my poll from three weeks ago:

Okay, I think I'm beginning to understand. It looks like my current version of Edge is NOT the latest, so it probably doesn't come with regular windows updates. If I download the latest version, will it act as an update and keep all my preferences, or an entirely new browser with a clear cache, all my favorites removed, etc?

If you dowload and install the new version of Microsoft Edge from then

Your favorites, passwords, and basic settings (from Edge Legacy) will carry over to the new Microsoft Edge automatically.

Thank you for all your help! :D


Quote: but I keep everything up to date on my computer (windows 10 laptop)

See Isabel's tip that you need to turn OFF Win10 "S mode" to be able to install Google Chrome.

Looks like Duo didn't post my comment... I already have Chrome and it's working, so I'll use that for now. Still, looking forward to when this is fixed so I can return to using this on Edge.

Windows 10 S mode exists for a reason. Please don't advise people to turn it off without fully understanding the implications of doing so.

Please open the web console in your browser and check for a specific JavaScript TypeError message.

You can do this on Firefox with the F12 / Ctrl + Shift + K hotkeys.

There seems to be a new web rollout today Monday, 03. February 2020.

This update definitely broke Mozilla Firefox V52.9.0esr.

The web portal was working fine this weekend.

Browser console error message when trying to access the Home/Learn page, lingot store, starting a new practice session:

TypeError: r.compact(...).map(...).flat is not a function: app-d12d541d.js:9:15058

Right now I have no other chance to quickly test it with:

  • Mozilla Firefox Quantum V68esr, v69-70, most recent V71-72
  • Google Chrome V77-78, latest V79
  • Microsoft Edge

I sent in a very detailed bug report including JavaScript react StackTrace under bug id 1762983 but cannot tell how many people are affected on Chrome, Firefox Quantum, Edge or Safari.

I am using Microsoft Edge, so will the bug eventually be fixed, or must I go about changing my browser (I would prefer not to, of course...)

In the past, how long before these bugs are fixed, usually?

TIA for ANY additional info Thomas! I am suffering withdrawl from the Owl!!

[deactivated user]

    I'm also using Microsoft Edge and am getting the same problem. Windows 10 up to date. Safari on my I-pad is ok.


    Quote: I'm also using Microsoft Edge and am getting the same problem.

    According to this table Microsoft Edge V79 should support this Javascript function.

    It this true? Have you tried it already?

    I am not exactly sure where the V79 version comes from....maybe as Edge is now based on Chronium?

    [deactivated user]

      @Thomas.Heiss I downloaded the new Edge (V79.0.309.71) from and I can access the tree now. Thanks for your help.

      Well shared. Others will benefit.

      me too! I tried searching for duolingo on multiple search engines but it's still not working

      I submitted a bug report for Microsoft Edge Browser, and referenced your bug report Thomas (1762983) because I wanted to let them know it's the same problem, and I don't know how get a specific 'console error message'... I can only report that my lessons aren't working : ( They gave me #1763131 for this Microsoft Edge bug report.


      Quote: They gave me #1763131 for this Microsoft Edge bug report.

      Have you already posted a link to this thread id?

      You can answer them on the auto-reply message and add on top new informations.

      I referenced your bug report, but did not link the discussion thread. TBH, I didn't know what I was doing, I was just trying to figure out what to do using your very helpful comments!

      I guess it worked though, per all the comments that Microsoft Edge is working now...

      As with many others, I'm only getting a blank white screen. My network utility can't even get a ping from any Duolingo server. However, I did get Google Chrome to work. Safari 11.1.2, my usual browser, still doesn't work.

      For me the tree is not accessible on Microsoft Edge, but I can access it on Google Chrome.

      Yes, indeed, thanks to this discussion, I have reverted to Chrome, and it's working. Whoopee!

      I've got the same problem. I am using Microsoft Edge.

      So many people have this problem. Duo NEEDS to fix it!!!!

      I have the same problem. White screen on the "learn" page. I can access the stories. Using win 10/edge

      Duolingo is now working for users with "Legacy" Microsoft Edge as well as for those who have updated to the new version.
      • 1052

      well it came back for me too,on google chrome older non-updateable version. I hope duoLingo learns from this unnecessary outage, there are many people who cannot or will not "upgrade" their browsers, OS versions, or machines, just to access a website. And there is NO reason why they should do so , perfectly standard HTMl can handle their website. I don't need bells and whistles, such as the useless icons cluttering up the questions. I speak as an experienced It developer with a lot of web sites under my belt. Complexity makes problems and achieves little.

      I can confirm that Mozilla Firefox V52.9.0esr works again.

      I occasionally see that Firefox is freezing when it is loading several React JS files which was not the case in 2019.


      With some (heavy) performance restrictions like lesson freezes, high CPU load, occassional blackscreens, requiring constant browser restarts on this older Laptop when I compare it to Memrise/Mondly/Lingvist.

      Actually this started with the "mobile app look" which was rolled out to the web in 2019 removing the previously web code which worked really good (on this older system) in 2016-2018 and much more smoothly.

      I had already written about these facts in the other official 1-2 frontend introduction / changes thread from staff in 2019.


      Unfortunately, turning off the "Hardware acceleration" in Firefox did not fix completely those issues on this older hardware / OS.

      Another step might be to try to downgrade to a previous Intel graphic driver version on this older Laptop chipset
      (the most reason version was much more unstable, but the minimum required version for Firefox and activing WebGl was no real help too).

      I will link my comment in the other two frontend announcement threads if I fine them in the next days / weeks.

      Q: Has anyone of you been having the same issues with Firefox V52.9.0esr using Duolingo (but not with any other website) since 2019?

      Any further recommendations you can give to me which eventually solved those lesson freezes?

      I might open a new Troubleshooting thread in the next couple of weeks/months as this is clearly not (only) related to the website update / rollback from this week or React JavaScript library introduction.

      i have a white screen today connected via google chrome - what can i do?

      3 Feb 2020 Same for me. I can only access the forum, even after turning my device off and then on again.

      my duolingo simply cannot be accessed on my mac book pro. I get just a white screen

      This is unbelievably frustrating!

      Tell me about it!

      I have also een white screen. Are there troubles?

      I have a white screen too, since yesterday evening, and can only Access the stories. My PC has functioned perfectly for Duolingo up to now.


      same here, only a white screen but I can get stories and forum

      Me too, just getting started for the day, no exercises to be seen - working ok on app on Android, but that's a pest, prefer the laptop. Hope we get an answer.

      Don't know if others have this problem, but I cannot access my profile as well.

      Same. Blank profile page. Including when I click on others profile pages.

      I'm only getting a WHITE SCREEN when I click on the lesson tab in my forum or click on the link in the "study reminder" e-mail. The same when I put in DUOLINGO in my web browser. What's up? I'm using Safari version 11.1.2 and I've NEVER had this problem before. Please respond as I'm missing studying! Thanks Janmunroe


      Quote: What's up?

      Maybe the React UI Javascript library was updated yesterday and rolled out to their servers or new Duolingo web code was developed/changed for a specific newer React version?

      Quote: I'm using Safari version 11.1.2

      Try to upgrade your system and use Safari 12+.

      As far as I understand it right now:

      This should have the JavaScriptCore engine Array.flat() function which the JavaScript scheduler.production.min.js file (React 0.18) is calling which results for older browsers in the nasty error message:

      "r.compact(...).map(...).flat is not a function"

      Thomas, thank you for all your help (and patience) today!

      You are appreciated!!

      Yes thank you very much. I am happy that Duo works again in EDGE. What an intensive 'bad'' Duo day was it yesterday also for you.

      I am experiencing exactly the same - cannot learn but can access stories only. Using safari/apple Tried reloading via google everything..... Any suggestions?

      white screen can't access learn option

      Duo went blank on me also. I am using Windows 10. I sometimes use Google and other times Bing. I can access Duo on my phone, but not on my laptop or desktop (both windows 10). It is as if the site is being blocked. The address appears, but the screen is white/blank?

      BTW I am also using Edge.

      Microsoft has released a new version of Microsoft Edge.

      The "legacy" version of Edge uses this logo:

      The new version uses this logo:

      If you are still using the "legacy" version, and can't access your Duolingo Tree, you can download and install the updated version of Microsoft Edge -

      Microsoft will be upgrading all Windows 10 users to the new version over the coming months.

      Yes thanks - I now have the new icon

      Thanks, very useful to know.

      I can't use duolingo today because the screen is white

      I switched over from using Safari 11 to using Google Chrome. It worked fine then. UNTIL THE NEXT "IMPROVEMENT" THE BOYZ IN THE BACKROOM COME UP WITH!


      Thanks for backing me up yesterday.
      Good to see you around here.

      You are quite knowledable on Win10 and Edge (Legacy) browser history and current changes.

      Very helpful that you joined this thread.

      Thanks for taking your time. day I will hopefully upgrade computer hardware and all software (new RC helicopter flight simulators got quite demanding, especially for VR)....

      Best regards from Germany

      Here are some other suggestions how to fix browser problems from the last few days:

      Specifically check the comment from OfficeTrotter how to fix concrete shown JavaScript (TypeError) error messages in the web console (e.g. "Cannot read property 'find' of undefined at home-HomePage-149b3317.js:1") with the Chrome DevTools:

      I went to Application -> Clear storage and clicked "Clear site data".
      After reloading, I had to log in again, and then the Learn tab loaded.
      So it was some cached file that was the culprit, after all. Or an update that broke the cached file, whichever way one wants to look at it!
      • 1444

      Same issue here...

      White screen with ALL web browsers (Firefox, Brave, Edge). I confirmed that all of the web browsers are the most recent updated versions. One thing I noticed... Today, I could connect each web browser for one session only, without issue, but after that any subsequent attempt to visit, displays a white screen only. Deleting cookies, flushing the browser cache, etc., does not work.

      Please can Duolingo support help, thank you!
      • 1444

      One contributing factor might be... Modern web browsers have privacy function that resist fingerprinting. This might be a salient issue. If Duolingo attempts to detect versions; in Firefox for example it would detect version 57 (well below that of the actual version). The fix (if this is the issue), just serve the pages, don't try to serve different versions based upon what is detected - As privacy is increased in newer browser versions, this may be of increasing impact (if fingerprinting resistance is the issue). Instead, just serve standard pages (which would not need browser version detection). This may or may not be the issue. In Firefox the setting for this is found in the "privacy.resistFingerprinting" configuration option.

      I cannot get into Duolingo. All I get is a white screen. Have rebooted. Tried going in from Official WebPage. Nothing. My husband is on Duo now. His is fine. I can get the app on my phone????

      I got a blank screen

      Duolingo does not work on my Android. The screen is just white. It is a brand new Samsung Galaxy and I have downloaded the Duolingo-app. Duolingo just worked for some few days. What to do?

      Learn a language in just 5 minutes a day. For free.