Thank you for your valuable replies.

Quote Originally Posted by SamT View Post
"ExcelVB" sounds like the name of a Procedure, Module or Workbook. From the error messages, Excel thinks it is the name of a Workbook.
I agree. But it's not a name I ever used; nor could I find that name in any recent "*.xl*" files. Is there any way to see where in the world Excel sees that name?

Quote Originally Posted by SamT View Post
... test the code thoroughly ...
You're right; I didn't do that just now. It was thoroughly tested before, and I planned to test it after the split. I didn't see a need to test it during the split, as I didn't foresee any such problems. Well, hindsight is 20/20.

But now my problem is how to get rid of those error messages that appear before I do anything with the code. If I want to follow your advice, I first need a clean system again.