XL2000: VBA Error on Macro Startup if You Open Multiple Excel Instances with RefEdit Control

When you open an Excel workbook (.xls file) or add-in (.xla file) that uses the RefEdit control, you may receive one of the following unhandled exception error messages in Microsoft Visual Basic for Applications (VBA) on the first line of code to run in the project. -or-

The problem occurs if multiple instances (for example, four or five) of Excel are running. Each instance contains workbooks or add-ins that also use the RefEdit control, and all of the temporary locations that hold extenders already have open libraries by the same name (one for each instance of Excel that is using the RefEdit control).

When a VBA project that contains the RefEdit control is loaded, VBA creates a control extender for the RefEdit type library. The formation of the control extender is similar to any control that you add to a UserForm. If multiple instances of Excel are running, Fm20.dll may fail while it attempts to create this extender. This failure can result in a VBA runtime error when your code is eventually called.

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, submit a request to Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language. The English version of this fix should have the following file attributes or later: After the hotfix is installed, the following files will have the listed attributes or later:

Microsoft has confirmed that this is a problem in Microsoft Excel 2000.

Because the error occurs before the macro code is run, Excel starts the VBA Integrated Development Environment (IDE) and stops at the function entry point. This is similar to the behavior that occurs if VBA detects a compile error.

Steps to Reproduce the Behavior

1. Start Excel 2000, and then create a new workbook.
2. Press ALT+F11 to start the VBA IDE.
3. On the Insert menu, click UserForm to add a new UserForm to the workbook.
4. Add a RefEdit control to the UserForm.
5. In ThisWorkbook, paste the following code in the Open event:

   Private Sub Workbook_Open()
      Dim x as Object
   End Sub
   					

6. Save the workbook to a local folder.
7. Start another instance of Excel.
8. On the File menu, click Open, and then open another copy of the workbook that you just saved.
   
   NOTE: You may receive a macro warning dialog box followed by a File in Use dialog box that asks you if you want to open the Excel workbook in read-only format. Click Enable Macros, and then click Read Only.
9. Repeat steps 6 and 7 three or four more times, until instead of the dialog box, you receive one of the error messages that is described in the "Symptoms" section.

For additional information about control extenders in VBA, click the article number below to view the article in the Microsoft Knowledge Base: