I doubt anyone will ever experience this but perhaps my solution might help someone who happens to fall into the same pit of COM-debugging hell as I have.

I´ve got some tests where I use Word Automation to start an application and modify some documents. The documents are created beforehand and opened after which I perform some actions and then assert that the result is what I want it to be.

Now, however, my tests suddenly stopped working.

On one line:

ShapeCount = section.Range.ShapeRange.Count,

My application throws an exception with the ever so helpful message:

Exception from HRESULT: 0x80010105 (RPC_E_SERVERFAULT)

The first step – try it in VB. If I opened the exact same document the error wouldn’t appear. All I had done to the documents at this point was opening them and reading some information. In addition to this, I could read the ShapeRange object in several previous sections.

I just tried, for the sake of trying, to open the document as Visible and tada! It works!

It´s certainly not an explanation and it bugs me to have to specify the documents as Visible when in fact they´re not, the entire application is hidden but still, it works. Perhaps it will for you too?