The SharePoint Products Configuration Wizard, commonly called psconfig, is what actually applies a cumulative update or service pack to a SharePoint farm after the binaries have been installed. It is also one of the more fragile parts of the patching process. When it fails partway through, the farm is left in an inconsistent state: some servers upgraded, some not, and the wizard often refusing to simply run again cleanly.
The two errors that usually show up
The most common failures during a psconfig run are an SPUpdatedConcurrencyException or an EndpointNotFoundException. Both point to the same underlying issue: SharePoint services on the server are actively interfering with the configuration process while it tries to run, usually because a service that should be idle during the upgrade is still active.
The fix: stop the interfering services first
Before re-running psconfig, stop the following Windows services on the affected server:
- SharePoint Tracing Service (SPTraceV4)
- SharePoint Administration (SPAdminV4)
- SharePoint Timer Service (SPTimerV4)
- World Wide Web Publishing Service (w3svc)
Search services in particular need to be stopped manually rather than assumed to be idle, since they can continue running background crawl or index activity that conflicts with the upgrade process.
If psconfig still refuses to run: clear the stuck upgrade flag
A failed psconfig run sometimes leaves a farm level property stuck in a state that tells SharePoint an upgrade is still in progress, blocking any attempt to run it again. Clearing it with stsadm resolves that:
stsadm -o setproperty -pn command-line-upgrade-running -pv "no"
Once that property is reset and the services above are stopped, re-running the Configuration Wizard, either through Central Administration or the psconfig command line tool directly, typically completes successfully.
Confirm the outcome afterward
After any patching attempt, successful or not, it is worth confirming every server in the farm actually landed on the same build. We cover exactly how in our guide to checking your SharePoint farm build version, which also covers the related Get-SPProduct -Local command for spotting a server that silently fell behind.
If patching your SharePoint farm has become something you dread every month rather than a routine task, that is usually a sign the farm needs a proper health check rather than another one off fix. Our Microsoft 365 team can take a look. Get in touch if a stuck upgrade has you stuck too.