Excel is crashing
 

Does anybody know of solutions for problems like this:

I open a Workbook with a UserForm with MultiPages on it. I use the
form, and then I decide I want to save a copy. I click "Save As..."
and I save it in a new directory.

I open the New Workbook and I use it. It works fine. I decide I want to
save another copy of this workbook. I click "Save As..." and then I
save it in a new directory.

I open the Second New Workbook and it crashes when I click on the
UserForm Tabs. I cannot debug whatever it is causing this because Excel
dumps.

Any suggestions?