Steps to replicate the issue (include links if applicable):
- Open https://en.wikipedia.org/wiki/%22P%22_Is_for_Peril on the desktop with the Vector 2022 skin.
- Click "Add interlanguage link" in the right-hand sidebar.
What happens?:
A bubble saying "An unknown error occurred" appears at the top.
What should have happened instead?:
The interlanguage link dialog is supposed to appear.