DOCUMENT:Q238341  11-FEB-2002  [visualc]
TITLE   :FIX: Opening a DSP or DSW File in Explorer Crashes Visual C++
PRODUCT :Microsoft C Compiler
PROD/VER::6.0
OPER/SYS:
KEYWORDS:kbservicepack kbAutomation kbVBScript kbVC kbVC600bug kbDSupport kbGrpDSTools kbNoUpdat

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The information in this article applies to:

 - Microsoft Visual C++, 32-bit Enterprise Edition, version 6.0 
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SYMPTOMS
========

Double-clicking or pressing the return key with a project file (.dsp) or a
workspace file (.dsw) selected in Windows Explorer causes Visual C++ to crash
with the following error:

   The instruction at "0x50c2b90d" referenced memory at "0x00000000". The memory
   could not be "read".

NOTE: The addresses in the error message may vary depending on the operating
system and the service pack installed.

CAUSE
=====

This problem occurs when you have a macro file (.dsm) loaded in the Visual C++
integrated development environment.

RESOLUTION
==========

When opening projects or workspaces from Windows Explorer, Dynamic Data Exchange
(DDE) is used to open these files in a currently running instance of Visual C++.
If Visual C++ is not running, the program will start if you double-click a .dsp
or .dsw file. The presence of a macro file interferes with DDE, thereby causing
this crash. Follow these steps to turn off this feature for the .dsp and .dsw
file extensions:

1. Start Windows Explorer.

2. From the View menu, select Folder Options. (If you are using Windows 2000,
   then View is found under the Tools menu.)

3. Click the File Types tab.

4. Under Registered File Types, select Project File, and then click Edit. (In
   Windows 2000, click Advanced.)

5. Select Open with MSDEV from the Actions list, and then click Edit.

6. Clear the Use DDE checkbox and click OK.

For the .dsw file extension, repeat the above steps except in Step 4 select
Project Workspace.

If you want to reverse the changes you made using the above steps, then do the
following:

1. Follow the first six steps described above.

2. Select the Use DDE checkbox.

3. Type Open("%1") in the DDE Message edit box.

4. Type msdev in the Application edit box.

5. Type System in the Topic edit box.


STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article.

This problem was corrected in Microsoft Visual C++ .NET.

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

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

1. From the Tools menu, select Customize, then click the Add-ins and Macro Files
   tab and browse for an existing macro file (DSM).

   If a macro file does not exist, then create a new one and add a Visual Basic
   Script macro to the file. It is essential to have some text in the macro
   file.

2. Quit Visual C++.

3. Start Windows Explorer, and then double-click an existing DSP or DSW file.

An error will occur.

REFERENCES
==========

For more information on Visual Basic Script macros, see the following topic in
the MSDN Online Libraries:

   http://msdn.microsoft.com/library/devprods/vs6/visualc/vcug/_asug_home_page.3a_.vbscript_macros.htm

Additional query words:

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Keywords          : kbservicepack kbAutomation kbVBScript kbVC kbVC600bug kbDSupport kbGrpDSTools kbNoUpdate 
Technology        : kbVCsearch kbAudDeveloper kbVC600 kbVC32bitSearch
Version           : :6.0
Issue type        : kbbug
Solution Type     : kbfix

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