Help regarding 'System.Runtime.InteropServices.COMException' RRS feed

  • Question

  • Hi,

    While opening a visio 2010 through, I am getting the below error.

    An exception of type 'System.Runtime.InteropServices.COMException' occurred in ********.dll but was not handled in user code

    Additional information: The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)

    This has been happening since we upgraded our computers from Windows 7 to Windows 10.

    Would appreciate if someone can give valuable inputs on this.


    Thursday, December 5, 2019 12:47 AM

All replies

  • Well it might help to know the DLL throwing the exception as you did **** which means nothing to us. It could be a permission issue as Win 10 is tighter with security or a handful of other reasons. If you did a Google search note how many variations there are for this to happen.

    Bottom line it's not code but environmental. 

    Please remember to mark the replies as answers if they help and unmarked them if they provide no help, this will help others who are looking for solutions to the same or similar problem. Contact via my Twitter (Karen Payne) or Facebook (Karen Payne) via my MSDN profile but will not answer coding question on either.

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    Thursday, December 5, 2019 2:01 AM
  • Hi,

    Some people have encountered similar problems before, here are the possible causes and solutions I have found so far:

    1.While opening a project solution, sometimes user doesn't have enough priveleges to run some COM Methods. The most common solution is to run Visual Studio as an administrator.

    2. In the firewall settings of Windows, go to the "Exceptions" tab and check the "Windows Management Instrumentation" box to allow WMI to pass.

    3. The Windows service "DCOM Server Process Launcher" may have stopped. The solution is the "DCOM Server Process Launcher" service should always be set to Automatic for proper functioning of many .NET operations.

    4. The most likely cause: Your code (or some code you call) is calling a COM method that returns an unknown value. You can try to break when an exception is thrown. Go to Debug> Exceptions ... and use the lookup option to locate System.Runtime.InteropServices.COMException. Check this option to make it break when thrown, and then debug your application.

    Useful links:

    Hope it be helpful.

    Best Regards,


    MSDN Community Support Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact

    Thursday, December 5, 2019 2:44 AM