Receiving Error Message when trying to load All Releases under Test Cases

I am facing an issue whereby an error message is shown each time i try to load test cases from all releases. I can only view test cases per release. I am getting the following error message:-

"System.Data.SqlClient.SqlException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding."

Please advise on this error message and what can be done to solve it.

Thanks,

Arvind