- Terminate the PSConfig task through the Task Manager.
- Go to Administrative Tools > Services. Stop the SharePoint Timer service.
- Clear the config cache
- In Explorer, go to C:\ProgramData\Microsoft\SharePoint\Config
- Delete all files EXCEPT the cache.ini file
- Open the cache.ini file, change the number shown to 0 and save
- Start the SharePoint Timer service
- Wait for the cache files to populate again
- Open SharePoint Management Shell as an administrator and run the command:
Psconfig.exe -cmd upgrade -inplace b2b -wait -force
Now in Central Administration and navigate to Upgrade and Migration > Check Upgrade Status. You can verify the upgrade completed successfully.