.net - A reference to the dll could not be added

Question

When I add a .dll file as a reference in C# application it shows an error :

A reference to the "....dll" could not be added.Please make sure that the file is accessible and that it is a valid assembly or COM component.

ILDissassembler says there is no valid CLR header so I try to register it using regsvr32 and that gives me another error:

The module "" was loaded but the call to DLLRegisterServer failed with error code '0x80004005'

I am using VS2010 ultimate version on a 64bit Windows 7 machine. What could be the problem?

Thanks for any hints/replies

Answer 1

The following worked for me:

Short answer

Run the following via command line (cmd):

TlbImp.exe cvextern.dll        //where cvextern.dll is your dll you want to fix.

And a valid dll will be created for you.

Longer answer

• Open cmd

• Find TlbImp.exe. Probably located in C:Program Files (x86)Microsoft SDKsWindowsv7.0ABin. If you can't find it go to your root folder (C: or D:) and run:

  dir tlbimp.exe /s              //this will locate the file.
  

• Run tlbimp.exe and put your dll behind it. Example: If your dll is cvextern.dll. You can run:

  TlbImp.exe cvextern.dll
  

• A new dll has been created in the same folder of tlbimp.exe. You can use that as reference in your project.