KB171550 - FIX: Recompiling with SP2 Breaks Binary Compatibility

Article ID: 171550

Article Last Modified on 12/10/2003

Microsoft Visual Basic 5.0 Control Creation Edition
Microsoft Visual Basic 5.0 Learning Edition
Microsoft Visual Basic 5.0 Professional Edition
Microsoft Visual Basic 5.0 Enterprise Edition

This article was previously published under Q171550

SYMPTOMS

After adding functionality to a server application (.EXE, .DLL or .OCX) and recompiling several times with Microsoft Visual Basic version 5.0 with Visual Studio Service Pack 2 installed, the following errors may occur:

Existing client applications may fail when attempting to create an object type from the server.
The Object Browser may not display all of the classes of the server or all of the members of a particular class of the server.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This bug has been fixed in Visual Studio 97 Service Pack 3.

For more information, please see the following article in the Microsoft Knowledge Base:

170365 : INFO: Visual Studio 97 Service Packs - What, Where, and Why

For a list of the Visual Basic 5.0 bugs that were fixed in the Visual Studio 97 Service Pack 3, please see the following article in the Microsoft Knowledge Base:

175450 : INFO: Visual Basic 5.0 Fixes in Visual Studio 97 Service Pack 3

MORE INFORMATION

NOTE: The problems caused by this bug are difficult to reproduce consistently.

Steps to Reproduce Behavior

Make an ActiveX DLL (Knowledge Base article 173407 contains the specific steps). After the first compilation (to create the DLL), copy the DLL and rename the copy to <filename>.CMP. This will create a file that will not be overwritten by future recompiles. (CMP is shorthand for compatible.) Then set the server project properties for version compatibility to Binary and refer to the .CMP file.
Add new functionality to the server without changing any existing functionality. Recompile the server to a new DLL. Make a copy of the DLL with the extension .CMP.
Change the server project version compatibility file to the new .CMP file. Add more functionality and recompile to a new DLL. The problems may not appear until the third generation of the DLL has been created.

One workaround for the problem is to recompile the server project to a new DLL and use the new DLL as the binary compatibility file listed in the project properties dialog.

Keywords: kbbug kbfix kbvs97sp2fix kbvbp500sp3fix KB171550