So one of the things done by SET code is that we take over action=edit... To avoid the client downloading all the page content twice along with other unnecessary things, the server side tries to figure out whether the client is expected to load VE or not. If VE will load, it prevents EditPage from running. Unfortunately this leaves us with a very empty page until VE loads (theoretically - due to bugs it has been known to break in the past and leave the user with the blank page). I think we should put some sort of 'VE should load soon... If not, click here to force wikitext mode and here to report a bug'-type message in there.
Customize query in gerrit
|mediawiki/extensions/VisualEditor||master||+3 -0||Give a useful message in the temporary blank edit screen|