I have a C++ code which I use to open an assembly file via the Application.Documents.Open method. Before opening the file, however, I would like to be able to determine if all references (i.e. all the individual part files making up the assembly) can be found. At the point of the code where I would need to make this determination, I have the Application object and the name of the assembly file that I wish to open. Is there an API function which will allow me to make the necessary determination prior to calling the Application.Documents.Open method? That way, if there are unresolved references, I can choice not to call the method and simply return from my code with an approprite error message. Thanks!