Sys-firewall has failed to start ascii codec can't encode character \xe4 in position 31

[apparatus]

UnicodeEncodeError in starting imported VM in R4.2

Had the same problem. I reinstalled Qubes on the same drive. It seems, the installer did not purge the old installation and installed just the deltas. Results is a mismatch. Solution: I wiped the drive with gparted. (New partition table) And did a new clean installation. Anything is fine again.