I upgraded my MediaWiki instance from 1.35.3 to 1.36.2 a couple days ago. I have everything pretty much up and running again but when trying to use the Visual Editor I'm now getting this error. I use Nginx1.20.1 + Apache2.4 + PHP7.4-FPM, and I have enabled the http2 protocol both on nginx and on apache. Curl is version 7.68.0. Any pointers on how to handle this one?
Topic on Extension talk:VisualEditor
I have the same issue. Had to downgrade to HTTP 1.1 on the Nginx proxy