I have written a DLL using VFP 6.0 SP4. The DLL operates fine in VFP, but I'd like to also use it in, for example, Excel 97.


The code I use in VFP to use the DLL is:

oTest = CreateObject("refgen.ref_finder")
cName = oTest.getref("substanc", "numb", "AZZZD", 1)
Release oTest
MessageBox(cName)

The above code runs with no problems, and can be run multiple times without problems.

The code for my macro in Excel is as follows:

Dim oTest As Object
Set oTest = CreateObject("refgen.ref_finder")
cName$ = oTest.getref("substanc", "numb", "AZZZD", 1)
Set oTest = Nothing
MsgBox (cName)

This works fine when I run it once. However, if I run the same macro a second time I get the following error.

Run-time error '-2147467259 (80004005)':

Automation error
Unspecified error

The error occurs at the CreateObject line. To get the dll to work again, I have to shutdown and restart Excel.

Does anyone have any idea what this means ? I thought that maybe the object wasn't being destroyed properly, but it seems OK in VFP, and the debugger in Excel shows the value of oTest as being "Nothing".