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Q193172: PRB: Runtime Error 430 in Client After Server Type is Changed

Article: Q193172
Product(s): Microsoft Visual Basic for Windows
Version(s): WINDOWS:6.0
Operating System(s): 
Keyword(s): kbGrpDSVB
Last Modified: 11-JAN-2001

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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 the project type of an ActiveX server is changed from DLL to EXE and
recompiled, any client code that attempts to create an instance of an object
from the server generates the following error:

  "Run-time error '430' : Class does not support Automation or does not
  support expected interface."

CAUSE
=====

The error results from project compatibility and the change of the project type
from DLL to EXE. In project compatibility, Visual Basic preserves the Class ID
(CLSID) of the class but not the Interface ID (IID). Because the CLSID is
preserved, the class ends up being registered with two servers; the in-proc
server (DLL) and the local server (EXE). As you create an instance of the class
from a client, the class from the DLL is chosen. Because the class from the DLL
does not support the new IID, the above error occurs.

RESOLUTION
==========

Use the RegSvr32.EXE utility to unregister the old DLL server and re- register
the new EXE server to eliminate this error.

STATUS
======

Microsoft is researching this problem 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. Select Project1 in the Project Explorer and press the F4 key to bring up the
  Property Window. In the Property Window, change the value of (Name) to
  "Server."

3. Paste the following code into Class1:

        Public Test As Collection
   

4. Compile the DLL by selecting Make Server.dll from the File menu.

5. Start another instance of Visual Basic and create a new Standard EXE project.
  Form1 is created by default.

6. Select References from the Project menu and make a reference to Server.

7. Paste the following code in Form1:

        Private Sub Form_Load()
           Dim x as Server.Class1
           set x = new Server.Class1
        End Sub

8. Press the F5 key to run the project. No error is produced.

9. Switch back to the Server project. Select Server Properties from the Project
  menu. Select the General tab and change the Project Type to ActiveX EXE.

10. Recompile the project by selecting Make Server.EXE from the File menu.

11. Switch back to the client instance of Visual Basic. Select References from
  the Project menu. Remove the reference to Server.dll and check Server.EXE

12. Press the F5 key to run the project, and note that the following error
  occurs:

  "Run-time error '430' : Class does not support Automation or does not
  support expected interface."

Additional query words: kbdss kbDSupport kbVBp kbVBp600 kbCompiler kberrmsg

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

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