The page https://www.mediawiki.org/wiki/Help:VisualEditor/User_guide/he was created by the Translate extension. It's impossible to translate it using the source editor and trying to do this gives the user a link to the translation interface. But it seems to be possible to edit it using the VisualEditor. I didn't actually try to change anything, because I was afraid of breaking something badly.
I'm also not completely sure whether it's a VE or a Translate issue; I file it under VE because there are other issues in which VE behaves differently from the regular edit action, such as Bug 51459. But it may also be on the Translate side; CCing Niklas and Siebrand.
Version: unspecified
Severity: major