XL2002: <Projectname.Classname> Is Not a Valid Add-in

In Microsoft Excel, when you attempt to load an automation server, you may receive an error message similar to the following and the automation add-in is not loaded as expected.

This behavior can occur if the add-in DLL contains a special character in either the project or class name, for example, "Project�." Excel does not recognize project or class names with special characters.

To work around this issue, change the name of the project or class that has the special character, recompile the add-in, and then attempt to load the add-in. For example, change the project name from "Project�" to "Project1" before you attempt to load the add-in.

To load the automation add-in, follow these steps:

1. In Excel, on the Tools menu, click Add-Ins.
2. In the Add-Ins dialog box, click Automation.
3. In the Automation Servers dialog box, click Browse.
   
   You may receive the following warning:
   The file you selected does not contain a new Automation Server, or you do not have sufficient privileges to register the Automation Server.
   Click OK.
4. Find the renamed Automation Server in the list, select it, and then click OK.
5. The add-in should now be selected in the Add-Ins dialog box. Click OK.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.