Exception when loading .pdf file

Question

I have an app that is supposed to be able to print .pdf files. Right now, I'm trying to use the Reader's functionality to do so (through Interop.AcroPDFLib.dll and AxInterop.AcroPDFLib.dll, both v1.0.0.0). This app is being run on a Windows XP SP2 computer, and built with Visual Studio 2005.
When the program gets to the LoadFile function of the AxAcroPDF object that gets passed a valid .pdf file, a System.InvalidCastException is thrown. The message reads:
"Unable to cast COM object of type 'System.__ComObject' to interface type 'AcroPDFLib.IAcroAXDocShim'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{3B813CE7-7C10-4F84-AD06-9DF76D97A9AA}' failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)). (Interop.AcroPDFLib)"
I would greatly appreciate any help you can provide. Thanks in advance.

Answer 1

It's failing on all computers, including my dev machine. Does it matter that I don't want to display the file?
I'm looking at the example you've referenced, and I see a lot of display-related properties being set, such as Location, Size, TabIndex, etc. I didn't believe that these would be necessary if I only needed to quietly print the .pdf file. The block of code that's supposed to be doing this is as follows (and the call to Hide() should probably go above printAll(), but we're not even getting there at this point...):
axAcroPDF1.LoadFile(szFilePath);
axAcroPDF1.src = szFilePath;
axAcroPDF1.setNamedDest(m_szPrinter);
axAcroPDF1.printAll();
axAcroPDF1.Hide();
Also note that szFilePath and m_szPrinter are valid values at this point, since that was my first suspicion.