The offending page is https://he.wikipedia.org/wiki/%D7%A4%D7%95%D7%A0%D7%95%D7%A7%D7%95%D7%9C . Editing with VE works fine, but when saving we receive from the visualeditoredit action API module the following response:
{"servedby":"mw1228","error":{"code":"400","info":"parsoidserver-http: HTTP 400","*":"See https://he.wikipedia.org/w/api.php for API usage"}}`Could be related to T112286: Reports of 400 and 500 errors with Parsoid, but here no references are being added; even simple text edits don't work.
Issuing:
curl -H'Cache-Control: no-cache' https://he.wikipedia.org/api/rest_v1/page/title/%D7%A4%D7%95%D7%A0%D7%95%D7%A7%D7%95%D7%9C curl -H'Cache-Control: no-cache' https://he.wikipedia.org/api/rest_v1/page/html/%D7%A4%D7%95%D7%A0%D7%95%D7%A7%D7%95%D7%9C/15677590
didn't help.