The navision server is no longer responding after upgrade to Windows server 2008 R2

Hi all,

after upgrade to windows server 2008 R2 from windows server 2003, and upgrade SQL Server from SQL server 2005 to SQL server 2008 the Navision program faced some problem,

The program will disconnect automatically several times a day.

The error is

"The XXX server is no longer responding. This is probably because of one the following reasons:

  • The Server has been shut down, either manually or as an result of an error.
  • Network failure has occured.
  • A hardware failure has occurred on the server computer or on your computer."

I’ve already check to connection to server and the connection is ok without any RTO.

The problem same either using RDP or Navision Client.

Any ideas?