Failed to load widget
I encountered a bug and I think this is the way to replicate it to get "Failed to load widget".
I have 2 UR servers on 2 different computers. On my phone (S4, Android 4.3) I have a widget. After I change the server, the widget in the app becomes red and says "Failed to load". Also the quick actions notification re-enables by itself, even though I disabled it.
Luckily I made a backup of the widget so I didn't lose it :)
Thanks for reporting this and giving and telling us a way to reproduce it we will look in to it!