RunTime Error 13 and Type Mismatch...

Hello, I have a LARGE workbook that I have made with a lot of help from this forum and it has been working great until recently when I made some changes to it. Now I get this error,

RunTime Error 13
Type Mismatch

when trying to show some of the userforms. What is weird is it worked fine and I don't think I changed anything that would have affected it. I don't know where to start on this one so any help would be really appreciated.
thanks for your time.

EDIT: The Problem was solved By fixing Problems in the initialize script as suggested later in the thread.

Is it possible that there is an error in Range("B24"), or Range("G40") ?
For example "#DIV/0", this would return error 13

Thanks for everyone's help.