"Unable to start T-SQL Debugging. Could not attach to SQL Server process on ‘DatabaseName’. The RPC server is unavailable."

Error Message:

“Microsoft SQL Server Management Studio. Unable to start T-SQL Debugging. Could not attach to SQL Server process on ‘Database Name’. The RPC server is unavailable.”


If you receive the error message described above , when you try to connect remotely  with T-SQL Debugger at SQL Server, you can begin the troubleshooting by verifying the steps presented below.

These steps can help you, to identify the possible causes of the issue or can eliminate some of the possible causes:



Step 1

First it is recommended to verify if the configuration of the T-SQL Debugging  was done correctly. To verify that, you can follow the steps from the link: http://msdn.microsoft.com/en-us/library/cc646024(v=sql.100).aspx

Step 2

Try to connect locally on the same SQL Instance(normally the connection should be successful, if not that means the issue can be cause by a connectivity problem);

Step 3

Verify if the SQL Server Management Studio was started with Administrator permissions (Run as Administrator…);

Step 4

Verify if the account used to connect remote to T-SQL Debugger is in the Local Administrators Windows Group and has the right of ‘sysadmin’ on SQL Server Instance;

Step 5

Verify if the server and client are in the same domain. If they are not, you should make sure that the SQL services are running under the same account;

Step 6

If you have the Firewall enabled (on client and server), make sure the following ports are opened and can accept connections: http://msdn.microsoft.com/en-us/library/bb385831(v=VS.90).aspx

– TCP 139;

– TCP 445;

– UDP 137;

– UDP 138 ;

Step 7

Verify if the following services are started:

– TCP/IP NetBIOS Helper;

– Remote Registry;

– RPC Service;

Step 8

Verify if DCOM is active on the server and client. To do  that please follow the steps described in the link: http://technet.microsoft.com/en-us/library/cc771387.aspx ;

Step 9

You can execute the following test to verify the connectivity: use a laptop that is in the same subnet as the SQL Server, deactivate the firewall or add the necessary rules  and make sure the ports mentioned above are opened and ready to accept connections. Try to connect remote with T-SQL Debugger. If this test is executed with success, than probably the issue appears during the communication between the initial client and the SQL Server, at an intermediary device (for example a router);

Step 10

If you have intermediary devices between SQL Server and client, it is absolutely necessary to configure on this devices the  necessary rules and ports , so the communication between the SQL Server and the client not to be blocked;

Step 11

To verify if you have any issues with the permissions at DCOM level, you can activate the DCOM logging using the following link: http://support.microsoft.com/kb/892500;

Step 12

To verify if the DCOM works fine you can do the test from the following article http://support.microsoft.com/kb/259011/en-us



I hope that the steps provided above helped you to eliminate some of the possible causes of the error message.

Using the steps above you can start troubleshooting the error message and hopefully one of the steps, will provide you more information about the cause of the error message in your case.


Comments (4)

  1. CZ says:


    Can you please explain Step 5 further? What are the "SQL services"? If I use SSMS to connect to a MSSQL instance in another domain, there is only one SQL service, isn't it?

    Thanks very much.

  2. Godfather says:

    ipo manasila..nee enthu cheyum ???

  3. FLauffer says:

    Nice post to resolve debug issues..
    Thank you!