What do you mean by "I copy this project"?

If you mean the executable, create an installer rather than doing a copy and paste.

If you mean the code files, which line of code is highlighted? Are any of your references marked as "Missing:"?
There are several potential ways to fix it (including an explanation of "Missing") listed in the article What does this error mean, and how do I fix it? from our Classic VB FAQs (in the FAQ forum)