The same issue exists on MacOS / iOS.

It's not just that you can't switch documents while offline -- it's worse because when you do try to switch the app hangs and won't recover until you re-establish an internet connection. Even if you force the desktop app to quit and re-launch it, it won't revert to the last-open document -- it will try again to go online and open the document you tried to switch into (and will hang again). So if you're working offline and inadvertently try to switch to another Moo.do document, you will basically be locked out of using Moo.do for anything, period, until you get back to an internet connection. That's completely unacceptable. If Moo.Do can't be updated to access all documents while offline, then it should at least be prevented from switching and becoming unusable while offline.