SharePoint 2013 update conflict has occurred, and you must re-tr this action. The object SPWebApplication Name

While running the command to remove the dodgy extranet web app, got this error

Remove-SPWebApplication : An update conflict has occurred, and you must re-tr
this action. The object SPWebApplication Name=extranetppd.contoso.com was updated by Service Account, in the w3wp
(6180) process, on machine Contoso001.  View the tracing log for more
information about the conflict.
At line:1 char:1

Clear the SharePoint cache , refer to the technet article

Ran the command again, works absolutely fine

Remove-SPWebApplication https://extranetppd.contoso.com/  -Confirm -DeleteIISSite -RemoveContentDatabases