Problem:

Calling a Visual Basic class program in .NET from COBOL gives a 173 error message that the dll cannot be found (Load error : file xxxxxx error code 173. pc=0, call=1, seg=0).

Resolution:

First of all, make sure that the reference to the DLL is correctly set up.

In the REPOSITORY SECTION of the COBOL program, define a class as a reference to a class of the DLL. Make sure the reference is to a class and not a class method.

In the WORKING-STORAGE SECTION, define an object reference  to this class.

To call/invoke a method in .NET from a COBOL program use 'invoke' rather than 'call' to interface with other .NET languages.