DOCUMENT:Q190198  11-JAN-2001  [vbwin]
TITLE   :BUG: VB Fails When Editing Modules That Are Interdependent
PRODUCT :Microsoft Visual Basic for Windows
PROD/VER:WINDOWS:6.0
OPER/SYS:
KEYWORDS:kbGrpDSVB

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-------------------------------------------------------------------------------
The information in this article applies to:

 - Microsoft Visual Basic Learning Edition for Windows, version 6.0 
 - Microsoft Visual Basic Professional Edition for Windows, version 6.0 
 - Microsoft Visual Basic Enterprise Edition for Windows, version 6.0 
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SYMPTOMS
========

When your project contains modules that are heavily dependent upon each other
for variable definitions (such as a constant being the type of another module,
or passing a UDT defined in one module to another), editing one module will
gradually cause Microsoft Visual Basic to fail.

CAUSE
=====

The problem is caused by an illegal circular dependency cycle between the
modules.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. We are researching this bug and will post new
information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION
================

Steps to Reproduce Behavior
---------------------------

1. Create a new ActiveX DLL project in Visual Basic. Class1 is created by
   default.

2. Paste the following code in Class1:

         Public Type UDT3
            a As Class2
            b As Class3
         End Type

         Public Enum Enum1
            red
         End Enum

         Public Sub T(a As UDT3)
         End Sub

3. Add a class module (Class2) to the project, and paste the following code in
   Class2:

         Public Sub Test(a As Enum2)
         End Sub
         Public Sub Test2(a As Enum1)
         End Sub

4. Add a class module (Class3) to the project, and paste the following code into
   Class3:

         Public Enum Enum2
            Green
         End Enum

         Private Const C1 = Enum1.red

5. In Class1, add the following line of code as a third field to Type UDT3:

         c as long

Notice that Visual Basic fails after typing "c as ." It also crashes if you add a
member to Enum1 in Class1 or add a procedure and then press the F5 key.

Additional query words: kbDSupport kbdss kbVBp600bug kbVBp kbNoKeyWord

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Keywords          : kbGrpDSVB 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB600Search kbVBA600 kbVB600
Version           : WINDOWS:6.0
Issue type        : kbbug

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Copyright Microsoft Corporation 2001.