From the little bit  of code  you've shown, I'd suspect that you have a modal
form.

When you do the Show, processing of the subroutine will stall at that point
until the form  is closed again.

If your call to ProcessData needs the form to be open, then it won't be at the
time ProcessData is called.

BTW please do not type your code into your message - it could well be different
to the actual code. Use copy/paste to paste the actual code into your message.