This is one of the many errors I ran into while upgrading SharePoint 2013 farm.
An exception of type Microsoft.SharePoint.Administration.SPUpdatedConcurrencyException was thrown. Additional exception information: An update conflict has occurred, and you must re-try this action. The object SPUpgradeSession Name=Upgrade was updated by Domain\FarmAccount, in the PSCONFIG (7732) process, on machine Server01. View the tracing log for more information about the conflict
When I googled for this error, there are many fixes available. But I am going to write about the fix which worked for me. I may run into same issue again and save some time next time.
I got this error after step 2 of 4 while running PSConfig.
- stsadm -o setproperty -pn command-line-upgrade-running -pv No
//Running this command will skip the lock and move with the upgrade.
- Restart the SharePoint Timer service
- Re-run the psconfig