Steps to Reproduce:
- Open a Wikipedia article in the article namespace.
- Resize the window to a very small size so that the buttons overlap to the next line.
- Resize the window to the original size and see that the "Edit beta" button shows up, which was previously not there.
- Click on the new button to open VisualEditor.
Clicking the button produces an error message:
Error loading data from server: novenamespace: VisualEditor is not enabled in namespace 4. Would you like to retry?
Clicking OK closes this dialog, but immediately pops up another one of the same kind.
That the button wouldn't ever be visible, and that if it were, that it wouldn't give an error message about namespace 4.
Reproducible: Didn't try