It's not rolled back yet, currently it is refusing to do anything because "disc quota exceeded" despite me deleting 27 old backups (~11 GB). So I've contacted Multiplay support.
Edit, copy from Ubox forums: I think the problems are fixed. I rolled back to the backup from this morning (which I had expected was taken after the problems you saw, but from what I see, the chunk in smj's farm isn't there, so I guess it works).
I haven't checked the Nether yet.
If you see any errors like that, it would be useful if you include the coords of it in the future (or take a screenshot with F3 info on). Then I can find it much faster.
The OnTime stats seem to have reset. I'll try to fix them.