.net Com Add-in IDTExtensibility type library could not be loaded

[Julian Cropley]

I have been developing an Excel Add-in (EVE4) and had made many successful
builds of the project when I decided to try and make it backwards compatible
with excel 2000
I generated my own IAs for the office library and the excel library as PIA's
were not available. At some stage I started getting the following bizzare
error.

COM Interop registration failed. Type library exporter encountered an error
while processing 'EVE4.Connect, EVE4'. Error: Referenced type is defined in
managed component, which is imported from a type library that could not be
loaded (type: Extensibility.IDTExtensibility2; component:
c:\windows\assembly\gac\extensibility\7.0.3300.0__b03f5f7f11d50a3a\extensibility.dll).

Please note that something has been broken, now if i create a new add-in
with the .net add-in wizard, without adding any code to the project, I get
the same error!

I have since scrapped the idea of 2000 compatability and am using the office
XP PIA's (2002).

When I reinstalled Visual Studio .Net 2003, I was able to successfully build
the assembly, once. Then the next build the error returned.

 

[julian_cropley]

I have been developing an Excel Add-in (EVE4) and had made many successful
builds of the project when I decided to try and make it backwards compatible
with excel 2000
I generated my own IAs for the office library and the excel library as PIA's
were not available. At some stage I started getting the following bizzare
error.

COM Interop registration failed. Type library exporter encountered an error
while processing 'EVE4.Connect, EVE4'. Error: Referenced type is defined in
managed component, which is imported from a type library that could not be
loaded (type: Extensibility.IDTExtensibility2; component:
c:\windows\assembly\gac\extensibility\7.0.3300.0__b03f5f7f11d50a3a\extensibility.dll).

Please note that something has been broken, now if i create a new add-in
with the .net add-in wizard, without adding any code to the project, I get
the same error!

I have since scrapped the idea of 2000 compatability and am using the office
XP PIA's (2002).

When I reinstalled Visual Studio .Net 2003, I was able to successfully build
the assembly, once. Then the next build the error returned.

I have now solved the problem.
Whilst researching how I could get the IDTExtensibility2 interface from
somewhere else and circumvent the problem, I opened up an old VB6
Shared Addin project, I noticed that the IDTExtensibility2 Interface
was coming from a reference to MSADDNDR.dll, this reference however was
pointing to the installed application directory of my .NET Addin
project. The Application directory had been removed since the dll was
registered.
Somehow the MSADDNDR.dll had at some stage been part of my VS.NET Addin
project output.

Perhaps the VB6 designer and the VS.NET designer has the same GUID's
because when I reregistered the MSADDNDR.DLL in the Program
Files\Common Files\Designers\ with regsvr32. The VS.Net Addin built
correctly.

If anyone has an understanding of how this interaction could have
occured could they please explain it to me.

during the process of adding ia's and pia's and the general fiddling
around to acheive backward compatability