Below are the things you should take into consideration to rename an Active Directory User Account:

1. Check if the Domain controllers are running on the same version of Windows Server.
2. Ensure the necessary tools (such as Active Directory Users and Computers) are installed.
3. Check if the account is connected to a mailbox.
4. Create a backup of the domain Controller before renaming the account.
5. Check the permission on the account.
6. Check if the new account name matches the name naming policy.
7. Check the user’s group membership.
8. Disconnect the user account from Remote Desktop access.
9. Disable the user account before renaming it and then re-enable it after the renaming process.