FIX: More Than One Sub Main May Cause EXE to Crash (171555)

The information in this article applies to:

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

This article was previously published under Q171555

SYMPTOMS

If a project contains more than one Sub Main in different modules, it may run as expected in the IDE and compile without errors in either native or p- code, but will crash when run as an EXE. Visual Basic 5.0 will generate an application error, such as:

"The instruction at <address> referenced memory at <address>. The memory could not be "written"."

CAUSE

To avoid this problem, either include only one parameter-less Sub Main in the project, or install Visual Studio 97 Service Pack 2 (SP2).

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 2.

For more information on the Visual Studio 97 Service Pack 2, 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 2, please see the following article in the Microsoft Knowledge Base:

171554 INFO: Visual Basic 5.0 Fixes in Visual Studio 97 Service Pack 2

MORE INFORMATION

Steps to Reproduce Behavior

Start a new Standard EXE project(Project1) in Visual Basic 5.0.
Go to Project | Add Module, and add a .bas module(Module1) to Project1.
Add the following code to Module1:
```
      Sub Main ()
      End
						
```
Click on menu Project | Project1 Properties, select the General tab, and set the Startup object as Sub Main.
Click on Project | Add Class Module, and add a class module (Class1) to Project1.
Add the following code to Class1:
```
      Sub Main ()
      End
						
```
Make Project1.EXE, using either p-code or native code.
Run Project1.EXE. Note that Project1.EXE should crash with an Application Error.

Modification Type:	Major	Last Reviewed:	12/10/2003
Keywords:	kbbug kbfix kbvbp500sp2fix kbVS97sp2fix KB171555