error on upgrading from 2.2.50 -> 2.2.51

[mrpaulr]

Hello.
I have a problem with my gns3vm after trying to update from 2.2.50 to 2.2.51. Process hit an error and it doesn't work anymore. It is the second time I encounter an update error in the last months after trying to update to a new release (very fresh release :) ) but this time anything related to gns3 process it's dead, cannot restore...

Dec 2 06:38:22 xxxxx systemd[1]: gns3.service: Scheduled restart job, restart counter is at 185.
Dec 2 06:38:22 xxxxx systemd[1]: Stopped GNS3 server.
Dec 2 06:38:22 xxxxx systemd[1]: Starting GNS3 server...
Dec 2 06:38:22 xxxxx systemd[1]: Started GNS3 server.
Dec 2 06:38:22 xxxxx gns3server[2582]: Traceback (most recent call last):
Dec 2 06:38:22 xxxxx gns3server[2582]: File "/home/gns3/.venv/gns3server-venv/bin/gns3server", line 5, in
Dec 2 06:38:22 xxxxx gns3server[2582]: from gns3server.main import main
Dec 2 06:38:22 xxxxx gns3server[2582]: ModuleNotFoundError: No module named 'gns3server'
Dec 2 06:38:22 xxxxx systemd[1]: gns3.service: Main process exited, code=exited, status=1/FAILURE
Dec 2 06:38:22 xxxxx systemd[1]: gns3.service: Failed with result 'exit-code'.
Dec 2 06:38:22 xxxxx systemd[1]: Stopped GNS3 server.

It's a VM in a proxmox hypervisor, working for a few years... until now.
Any solutions to this? Except the one wich involves "reinstall" entire vm/server.
Thank you.