Unable to cast COM object of type 'Microsoft.Office.Interop.Outlook.InspectorsClass' to class type RRS feed

  • Question

  • Unable to cast COM object of type

    'Microsoft.Office.Interop.Outlook.InspectorsClass' to class type

    'Microsoft.Office.Interop.Outlook.InspectorsClass'. Instances of types that

    represent COM components cnnnot be cast to different types that represent COM

    components; however they can be cast to interfaces as long as the underlying

    COM component supports QueryInterface calls for the IID of the interface.


    I have a user that is using our MS Office plugin for outlook which allows them to save emails to our EDRMS system.

    The user has installed the plugin on a test machine successfully, but whenever he opens outlook now, he gets this error above.

    Any ideas?



    Monday, July 24, 2017 10:21 AM

All replies

  • Hello Greg,

    It looks like you are trying to cast a COM object to any managed type. To understand the cause I'd suggest adding any logging mechanisms to the code, so you could see what happens on an end user machine and find the exact line of code where it happens.

    Did you try to debug the code?

    What line of code exactly fires an exception?

    profile for Eugene Astafiev at Stack Overflow, Q&A for professional and enthusiast programmers

    Monday, July 24, 2017 12:23 PM
  • Which line of your code causes that error?

    Dmitry Streblechenko (MVP)
    Redemption - what the Outlook
    Object Model should have been
    Version 5.5 is now available!

    Monday, July 24, 2017 4:35 PM