When I'm trying to create a subpage to the MainPage like this:
http://localhost/wiki/index.php?title=Main_Page/Subpage
the following error pops up:
Error contacting the Parsoid/RESTBase server (HTTP 404)
This did not help. I use IIS on Windows 10.
Here are some lines from the log:
[DBConnection] Wikimedia\Rdbms\LBFactory::destroy: closing connection to database 'localhost'.
[DBConnection] Wikimedia\Rdbms\LBFactory::destroy: closing connection to database 'localhost'.
[http] HTTP complete: POST http://localhost/abwiki/rest.php/localhost/v3/transform/html/to/wikitext/Main_Page%2Fsubpage code=404 size=102 total=0.476158 connect=0.002153
[VisualEditor] ApiParsoidTrait::requestRestbase: Received HTTP 404 from RESTBase