A customer updated his TFS 2010 to 2013 in a new machine running Windows Server 2012 R2 and Sql Server 2014. Everything went fine, until after few days they started having an error whenever he tried to do a GetLatest or a Check-in or Check-out operation.
Error TF53001: The database operation was canceled by an administrator
Actually this error is not really informative, so I asked them to verify Event Viewer on the server (an operation you should always do whenever you have wrong behavior of your TFS). For each client operation that gave error they have this Event Error logged
Log Name: Application
Date: 19/02/2015 17:15:54
Event ID: 17310
Task Category: Server
A user request from the session with SPID 70 generated a fatal exception. SQL Server is terminating this session. Contact Product Support Services with the dump produced in the log directory.
This is an internal error of Sql Server, and we verified that SQL 2014 was in RTM, with no cumulative update installed. After installing latest Cumulative Update for SQL Server 2014 everything started working again. Since Cumulative Update usually address bugs in Sql Server product, it is always a good practice to keep your Sql Server up to date, and if you are experiencing strange Sql error, it could be the solution to your problems.