PRB: Mismatched Ole32.dll and Comcat.dll

ID: Q201364

The information in this article applies to:

Microsoft Windows NT 4.0
Microsoft Windows 95 OEM Service Release version 1

SYMPTOMS

All the following symptoms apply:

The following error message is displayed while performing the steps below:

Comcat.dll was loaded, but the DllRegisterServer was entry point not found. DllRegisterServer may not be exported, or a corrupt version may be in memory. Consider using Pview to detect and remove it.
- RegSvr32.Exe <Path for Windows\System>\ComCat.DLL on Windows 95.
- RegSvr32.Exe <Path for Winnt\System32>\ComCat.DLL on NT 4.0.
- Running the setup program created with Microsoft Visual Basic.

On the Project menu, clicking Components (CTRL+T) in Visual Basic 5.0 or 6.0 to display the Components dialog box, causes the following error:

Class not registered Looking for object with CLSID: { 000[ASCII 200]005-0000-0000-C000-000000000046 }

-or-

System Error &H80004002 (-2147467262). Not such interface supported.

Clicking OK displays the Components dialog box, but the components list might be empty.

Internet Explorer 4.0 or above gives the following warning

This page provides potentially unsafe information to an ActiveX Control. Your current security settings prohibit running controls in this manner. As a result, this page may not display correctly.

while accessing the following Web site
http://msdn.microsoft.com/workshop/samples/author/databind/eltdyn.htm
instead of displaying a table of chemical elements.

CAUSE

These symptoms are caused by the mismatched Ole32.DLL and Comcat.dLL files on the system.

Comcat.dll version 4.71 exports the following functions:

DllRegisterServer

DllGetClassObject

DllUnRegisterServer

DllCanUnloadNow

Comcat.dll version 5.0 exports the following functions:

DllCanUnloadNow

DllUnRegisterServer

DllGetclassObject and DllRegisterServer are forwarded to Ole32.dll.

Comcat.dll version 5.0 works with Ole32.dll up to version 4.71 and above; Comcat.dll version 4.71 works with Ole32.dll version 4.0.

RESOLUTION

Copy Comcat.dll version 4.71 on older operating system and register it.

MORE INFORMATION

Comcat.dll version 4.71 is distributable through Msvbvm50.exe. For additional information about Msvbvm50.exe, please see the following article in the Microsoft Knowledge Base:

Q180071 FILE: Msvbvm50.exe Installs Visual Basic 5.0 Run-Time Files

Please note that Comcat.dll version 5.0 is not redistributable.

REFERENCES

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

Q175156 PRB: Class Not Registered Error and Empty Components Dialog

Additional query words:


Keywords          : kbNTOS400 kbWinOS95 
Version           : WINDOWS:95; winnt:4.0
Platform          : WINDOWS winnt 
Issue type        : kbprb

Last Reviewed: May 21, 1999