While looking for a source of T226922 problem I noticed that moving any page in File namespace with no associated file (only a wikitext page) to any name in any wiki fails with error message:
The page could not be moved, for the following reason: Could not delete the page or image specified. (It may have already been deleted by someone else.)
If there is a reason to block renaming such pages (however I doubt that this should be blocked), the errer message is at least misleading.
Tested on the following pages:
https://commons.wikimedia.org/wiki/File:Nov%C3%A9_Dvory_(Sedlec-Pr%C4%8Dice).jpg https://pl.wikisource.org/wiki/Plik:Test https://test2.wikipedia.org/wiki/File:Test30.svg
(trying to rename to another name with the same jpg/svg extension)