I was upgrading a virtual host on System z from SLES 12 SP3 to SLES 12 SP4 and received the following messages at the end of the process.

There are some running programs that might use files deleted by recent upgrade. You may wish to check and restart some of them. Run 'zypper ps -s' to list these programs.
Executing 'zypper --releasever 12.4  --no-refresh  dist-upgrade --no-allow-vendor-change ': RuntimeError: Interrupted.

Migration failed.

Executing 'snapper create --type post --pre-number 83 --cleanup-algorithm=number --print-number --userdata important=yes --description 'after online migration''

Performing repository rollback...
Starting to sync system product activations to the server. This can take some time...
Rollback failed: Net::ReadTimeout: Net::ReadTimeout
I did some Goolging and didn't find much, so I manually issued the command that caused the "RuntimeError: Interrupted." message
'zypper --releasever 12.4  --no-refresh  dist-upgrade --no-allow-vendor-change
Everything seems fine, though I am not sure.

Do I need to restore the system back to where it was prior to the upgrade and start it over or am I ok at this point?