Not sure what should be done about this...
When I go to https://meta.wikimedia.org/wiki/Special:EditMassMessageList/MassMessage/Lists/Wikipedia_Library and try to edit the "Description" field and submit the edit, I get an error:
The following page is invalid:
- Wikipedia:A Taberna (novas)@gl.wikipedia.org
It's not clear to me what the issue is with this title.
Also, Special:CreateMassMessageList should maybe be smarter about this when creating lists using its import functionality.