{"error":"Unprocessable entity","code":422}

[Sinyaven]

This bug might be caused by Advanced Context Sentence 2 which I’m currently maintaining. I think it should be fixed in version 2.9.

[Userscript] Advanced Context Sentence 2

It seems like the problem was that the script was setting the referrer policy to “no-referrer” for all network requests. I think the original author of the script did this because with the default referrer policy, the Google Translate voice doesn’t work. In version 2.9 I have changed the policy to “same-origin” and starting lessons seems to work again.