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Margaret: How can I get rid of the ad for Duolingo Plus?

I have a terrible problem - don't know if it is Duolingo or what??! I am an older retired person with no money to pay for Duolingo Plus. I enjoy doing the exercises as I want to perfect my French. However when I finish the first lesson each time I start, the ad for Duolingo Plus comes up. Sometimes I do the exercises throughout the day so the ad can come up two or three each day. When it finally goes, a message comes up and i have to "debug" it. Twice Firefox has crashed. This is so frustrating! What can I do?

April 24, 2020




can you move your thread to the Troubleshooting(English) forum?



You can't turn off that Duolingo gives you announcements for Plus....they want your money.

What device are you on? Computer? Windows? What version?

What Firefox version do you use?

You can't do that much besides upgrading Firefox to the latest possible version (depending on the OS).

Maybe it is a new bug...but this sounds a bit strange that the Plus offering crashes your FF and it wants you to debug it.

You could open a ticket here and submit a screenshot and detail error message: https://support.duolingo.com/hc/en-us/requests/new

As long the Firefox browser does not crash immediately, you could open the web console with F12 / Ctrl + Shift + K hotkeys and scan for any red JavaScript error messages.
Click on the triangle (on the detail message) to open the full stack trace.

Include any detail error codes and detail messages + stacktraces when you post to developers.

It also makes sense to include the exact Firefox version (menu: Help/About Firefox) and what system you are on.


Have you tried with other browsers like Google Chrome (yesterday I heard there is another issue on Chrome) or Microsoft Edge?


As Thomas.Heiss suggests, the troubleshooting forum may yield better results.

One possible, and quite common, explanation for such a crash when a particular ad or feature appears is an old adblocker or similar program which has been overlooked or incompletely uninstalled from your system.

Your own system may simply need a good clearout and debug. ☺


Your own system may simply need a good clearout and debug.


A good way to accomplish this is to create a new Firefox profile and to start the Firefox.exe with the argument of the completely fresh user profile directory.

Then you will see if the crash (and debug) results from a corrupted browser addon/extension.

However, this will not fix concrete JavaScript error messages or issues resulting from ads (in the right corner ad panel).

Quite often the main cause of Duolingo is (too) old browser versions which result in incompatibility issues with newer JavaScript / 3rd pary stuff the Duolingo developers are using on their website.

I have some serious issues with the older Firefox V52.9.0esr version, but the Duolingo Plus (wide screen / single page) upgrade announcements to not crash and Firefox does not suggest to debug it.

What is funny:

2-3 days ago I had a running Memrise classic review session with 100 words; I had about 75-90% progress.
And I wanted to do a pause for 15-20 minutes.

Then I wanted to start a new Firefox browser window where I launched a new lesson in a freshly unlocked L0 skill.

And suddenly the whole Firefox.exe process instance crashed that badly, very weird.

Normally this does not happen and the browser addons, 100 Memrise sessions and especially Duolingo sessions only give the problem of lagging or freezing browser window instances.

So I always make sure that:

  • I regularly restart the browser before I start something new/bigger
  • I only do one thing (Memrise vs Mondly vs Duolingo)
  • I close the Duolingo windows/tabs once the 1-2 crown sessions (=lessons) have finished; I do not reuse the same window/tab

So this was a very new thing for me (I did not debug the crash report)...maybe it results from a very recent Duolingo website code update...maybe, maybe not.

I would be required to run one of the later Firefox Quantum versions (well, surely not the very latest one) do make it better compatible with the Duolingo web code; but this is currently not possible on this system / older Laptop.

Here are some links how different browser versions or devices (and OSes) behave:

There are so many more "blank screen" freezing / grading freezing threads :


2 words:

Ad. Blocker.



There are two type announcements on Duolingo:

  • Real ads on the right side (ad panel) from other sources.

Yes, theoretically you can block them if you really need/want to
(personally I run into a pretty bad **double loading / variable is undefined/NULL issue" with Camilo's audio userscript which I badly need and staff is unable to fix the issues with the right ad code; I even tried to report the details as a ticketid).

  • The internal Duolingo Plus blue full screen / single page announcements before or after lessons (when you Click through pages with the Continue button).

I have no idea how to disable / deactivate them.
You can't really limit what pages are presented next before or after a practice exercise or learning lesson.

The only thing which you can IMHO only due is to block some specific element/div/image content.
So if you do this, then you basically get "an empty blue page".

If some code in that internal blue Duolingo Plus upgrade announcement triggers JS error messages or Firefox crashing, you could probably block this.

But this then would mean that EVERY user runs into that crash/debug problem as Margaret gets them.
This obviously is not the case yet; otherwise the Troubleshooting forum would be bombed with the very same double / triple duplicate crashing threads about Plus errors.

And I would probably encounter them on Firefox V52.9.0esr too; well, not necessarily...maybe only the newest recently released version if not well tested.

Honestly, I do not think that it is required to install addons like "uBlock Origin" or uMatrix because the Plus ad crashes the Firefox instance and FF wants to debug it.

But without any concrete error message or way to debug a FF crash report it is hard to judge what is really going on on Margaret's computer and browser installments.

We actually had the case before that one user installed a very fresh version of Chrome or new Firefox (or Edge) with a new (or cleaned) user profile directory and deleted addons/extensions and all the previous problems were gone.

I am sure we can further help to block specific html/JavaScript code if the blue Duolingo Plus upgrade page might be the main issue on a specific browser and version (but I doubt it).

Maybe some new code rollout from the past days has broken specific browsers/versions like we have seen it previously in other freezing / empty page threads??

We really can't solve concrete issues if users do not post error messages / stacktraces; staff will have the same problem as they somehow need to reproduce the issue on THEIR computer / browser + version.

If I had cleaned the browser user directory, restarted the browser, launched Duolingo and I always run into the same crash error and debug message:
I would personally try to send in the crash report to Mozilla and FF developers so they (not Duolingo staff) can debug it.

Sadly to say, I am not skilled to debug a FF crash report or trace the FF instance for freezes.
Maybe Duolingo staff (=developers) is if you also include it in the bug report (ticketid)??

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