Function argument value, type, or count is invalid.

Another problem that is hard to locate. You build a COM project, either an EXE or any of the DLL types. After creating the EXE or DLL file, Visual FoxPro suddenly displays the error message "Function argument value, type, or count is invalid" and stops building the project. There is a DLL or EXE in the directory, but it doesn't contain any COM registration information. The TLB and VBR files are also missing.
If this happens to you, check the names of all methods and properties in the COM server that are neither protected nor hidden. Visual FoxPro doesn't properly generate the type library when names contain umlauts or other non-English characters. If you have a method like "GetDoppelgänger", this method would cause the error.