Error: "CoUnmarshalInterface returned error Acces denied" returned when debugging. (53696)

When debugging using debug-setup-wizard everything appears to be ok when set up.

But after entering debug-parameters an error: CoUnmarshalInterface returned error Acces denied is returned.

Stesp to check for troubleshooting:

1: Server permissions for debugging and full SQL Server debug requirements have been verified

2: Cheked to see if specific debug environment is supported by Toad.

3: Verify if a Windows Update done recently. One may need to reset ones security and unregistered the ssdebugps.dll.

RESOLUTION 1:

It appears that DCOM is not properly installed/configured on the server.Check with System Administrator to correctly configure DCOM and set permissions.

Incorrect DCOM Permission Settings:

SQL debugging uses Distributed COM (DCOM) to communicate between your client computer and the database server. You must configure DCOM to allow remote users to attach the debugger to a process on the database server.

By default, the correct DCOM settings are in place when SQL Server is installed. However, because of security considerations for the computer running SQL Server, you may want to restrict debugging access. Use the following as a general procedure for setting up DCOM on the SQL Server computer.

Important If you plan on running the debugger as any user other than the one running SQL Server, DCOM will need to be correctly configured first. Follow these steps to insure you have execution permission.

On the server:

1. Run DCOMCNFG.EXE.

2. In the Distributed COM Configuration Properties window, select the Default Security tab. Under Default Access Permissions, click Edit Default.

3. If group Everyone does not already have permissions, you may add it by clicking Add. Select the local machine name from the List Name From list. Select Everyone and make sure that Type of Access is set to Allow Access. Then click OK.

RESOLUTION 2:

If you prefer to limit debugging to specific users, you can add individual domain user accounts (e.g. domain\account) with administrator privileges. If you choose to add only domain accounts instead of Everyone, make sure to add the SYSTEM account as well.

1: Switch to the Applications tab of the Distributed COM Configuration Properties dialog.

2: Scroll through the Applications list and select SQLDBREG. Then click Properties.

3: Select the Identity tab and make sure that The interactive user is selected as the user to run this application.

4: Click OK to close the dialog box.

5: Restart the SQL Server service.

After applying those steps, your servers DCOM settings should look like this:

DCOMCNFG

|

|__ Application Tab

| |

| |_____ SQLDBREG

| |

| |______ Identity Tab

| |

| |_______ The interactive user

|

|__ Default Security Tab

|

|_____ Default Access Permissions

|

|______ Edit Default Button

|

|_______ Everyone (or domain\account and System)