A while back, I made  change to my SharePoint configuration to modify my alternate access mappings.  For some unknown reason, the mappings keep reverting back to their original state and when I go to modify them again, I get the following error:

An update conflict has occurred, and you must re-try this action. The object SPAlternateUrlCollection id=”lt;Web” App Name> was updated by <USER>, in the w3wp (<ProcID>) process, on machine <Machine>.  View the tracing log for more information about the conflict.

The solution to this is very simple – you have to clear the SharePoint cache on each machine in the farm.  The problem is that most of the documentation out there is very old, and they all tell you the cache is located in:

C:\Documents and Settings\All Users\Application Data\Microsoft\SharePoint\Config\

In my Windows Server 2012 environment, however, the actual location is:

C:\ProgramData\Microsoft\SharePoint\Config

Attempting to go to the All Users folder results in an Access Denied message, and then I have to search for what the heck is going on all over again.

If you need info on how to clear the cache, visit the following page: Clear the SharePoint Configuration Cache.  It has the updated directory locations in the instructions.  Also, if you are trying to figure out which GUID directory to update when clearing the cache, there is a comment from Joe Rodgers instructing you to run the following SQL statement in your SharePoint configuration database to retrieve the appropriate GUID:

SELECT [Id] FROM [Objects] (nolock) WHERE classId = ‘E6591A38-008A-4F23-A88F-36A181C7D4EB’