An user was created in Active Directory.
Added the same user to CRM users list.
Disabled the user in CRM and deleted the active directory.
Now, added Active directory account with the same user details and try to a user in CRM.
You will get the following error message.
That is because, when we enable the user the CRM looks for corresponding active directory account. As we have deleted active directory and added it again, the guid saved in CRM database is different.
You can check that in the SystemUser table, columnname ActiveDirectoryGuid.
For resolving the issue, just get the active directory guid of the user and update it in the CRM’s database and try enabling the user. After this, you won’t get any error messsage.