I'm had a very similar issue on 3.1 My harddrive was completely full. I tried to remove some files from inside the appVMs but that didn't clear any space on dom0 So I rebooted the system. After reboot one AppVM wouldn't start. I got the “Document is empty, line 1, column 1” Error. If I tried to go into the vm settings a pop up with the same error shows and text below - "This is most likely a bug in the Qubes Manager"
I looked into qubes.xml and it wasn't empty ( from size it looked similar to the other files in backup ) Even though I tried to replace it with some older versions from the backup but non worked. In the end I noticed the appVM folder had an empty firewall.xml file removing the file solved the start and setting issue I had to recover my firewall rules but that wasn't a big issue -- You received this message because you are subscribed to the Google Groups "qubes-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/qubes-users/2598d604-0c32-4b43-8a9b-fc1527ea9fc8%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
