Compile throws a “User-defined type not defined” error but does not go to the offending line of code

Question

Symptoms

This is a symptom specifically when compiling an Excel VBA project. The following error occurs:

User-defined type not defin

Answer 1

I had this problem with an ordinary VB6 program. It turned out that I had omitted a class definition, not a user-defined type. Apparently VB saw something like "Thing.name" and assumed Thing was a UDT. Yes, it's a serious VB6 bug, but you could hardly expect Microsoft to support something they sold sixteen years ago. So what versions of the various products involved are you using? This is only interesting if it occurs with a product that MS supports.