Dangers to AD account's username ID being renamed

This has struck us finally, where some users who have had account IDs changed in the AD starts experiencing problems accessing the site.

For example, I was once mydomain\kong kong  now I have had my ID changed to mydomain\kong lo

You might find the problems of logging into SharePoint site becomes intermittent or seems to work but then suddenly stops working.

You will also find that it is possible that adding the old account ID's access can still work. Although sometimes, SharePoint will prevent you doing it by warning the account is not unique.

It is best for situation like this to do an STSADM -o migrateuser command for these users in order to get rid of the the anomaly with the old account ID lying around in SharePoint's site collection user table.

See post below.

http://littletalk.wordpress.com/2009/12/14/the-user-does-not-exist-or-is-not-unique/

However, the thing to be most careful about is if this has happened to a Service Account that is being used to systematically access SharePoint libraries from say a batch program on a Server.

Granting the access to the old now renamed account ID can have fatal consequences for the WebClient Service that runs.  It can crash it and the only way to recover it is to reboot the server or kill it via the task manager after knowing its process ID.

http://support.microsoft.com/kb/2548470

The crash can happen not immediately after granting the access to the old account ID, it can look like all is fine and even files can get written into SharePoint, until all of a sudden may be a Windows Server Audit process runs, it probably flags up the access violation and crashed the WebClient service causing the problem.