The LandPhil be honest, be honorable, be kind, be compassionate, and work hard.

This is only funny if you’ve ever worked with SharePoint.  Or really any enterprise level Microsoft product.  Or really any enterprise software product…

No, only funny to SharePoint folks: Leave SharePoint Alone

Props to Christian Buckley.

So you’ve patched SharePoint.  And then you’ve run the configuration wizard on all of the farm machines to actually apply the updates.  Or, perhaps you prefer to use the command line psconfig.exe.  In any case, you get the dreaded (and very generic and not at all helpful) “an update conflict has occurred, and you must re-try this action”.

Fair enough, it says you should re-try, so you do.  And you get it again.  Ad infinitum.

Turns out it’s a problem with the configuration cache on that machine.  You need to clear that out.  I found the steps here (http://support.microsoft.com/kb/939308, which is an article for SP 2007, but it worked for me on 2010.)

I’ll summarize them:

1. Stop the timer service
2. Go to <systemrootdrive>:\ProgramData\Microsoft\SharePoint\<GUID>
3. Open the cache.ini file and look at the number.
4. Backup the folder.
5. Delete all of the XML documents in the folder.
6. Edit cache.ini so that it only contains “1”.
7. Restart the timer service.

When you restart the timer service, it should rebuild the contents of that directory, along with changing the value in the cache.ini file.  You should also then be able to run the upgrade wizard (or psconfig.exe).