Steps to reproduce/actual result

For both https://test.m.wikidata.org/wiki/Q197002?uselang=en and https://test.m.wikidata.org/wiki/Q197002?uselang=mul,

1. Go to the link.
2. Click the edit button of the termbox.
3. Notice that the mul description field (which is at the top for ?uselang=mul and in In more languages or All entered languages for ?uselang=en) is editable, so enter something in it.
4. Try to save the edit.
5. Notice that the saving failed. The error message says Your change could not be published. You can try clicking the publish button again., but retrying of course won’t help, as the backend properly rejects mul descriptions.

Expected result

In step 3, the description field is hidden, disabled or otherwise makes it impossible to enter mul descriptions in the first place (and thus steps 4 and 5 don’t happen at all).