User load error

Hi all,

On CRM 2011 on- prem, RU11.

I have a user that is set up correctly, with full sys admin security roles. His AD account is active and in date. He can log on to the network.

When this user loads CRM, I get the following error:

Record Is Unavailable

The requested record was not found or you do not have sufficient permissions to view it.

All other users have no issues.

The user in question is set up as a user on other CRM environments on the same server, and has no problems.

Does anyone have any suggestions?

Thanks.