WebDAV says "Completed 28/05/2020" when webdav server completely down

I messed up my WebDAV server and had to change its URL; I forgot to change Joplin to the new location, and didn’t notice the problem because Joplin always displays the following message:

Completed: 28/05/2020 10:57
Last error: TypeError: Cannot use 'in' operator to search for 'd:multistatus' in null`

How do I interpret this message? Is this a plausible opportunity for improvement in Joplin?