Problem When Finishing Practice Tests
It seems that sometimes after finishing strengthening skills tests, some of those tests would just return the page back to the home page instead of showing the results. Then the address bar would just show this link: https://www.duolingo.com/#end-error
I always have to restart the test all over again just to finish my daily goal. I don't really mind the error for I consider it as an additional learning exercise, but it seems to be more frequent today.
Usually, when this happens, it is localized; meaning that it might be a problem between their servers and your area's/country's network. So it will just clear up within a few days; however, to avoid waiting months for a fix, I suggest to send a bug report here: https://support.duolingo.com/hc/en-us/requests/new in case Duo's IT team haven't discovered the issue yet and/or post a new discussion in the Troubleshooting tab because their IT team is frequently active in that forum. And in the mean time, set your xp gain to 1 to prevent lost streaks and continue with your intended experience goal.
J'espère que cela aide et bonne journée!