Just to clarify. I am trying to use the Print Voucher button.

First check spelling.  See Enter Parameter Value video.

Quite honestly though I believe that this is due to using a Navigation form as well as having Tab Control in the navigation form.  Both of which are frowned on at a minimum, if not down right discouraged due to the difficulty of using them.  Quiet honestly I have not use either for so long I have forgotten the proper naming to get to the controls.

A much better solution in my opinion would be to use the dymamic subforms as demonstrated in the extended cut of the Vehicle Maintenance video and introduced in the ABCD

Thanks for your response. Yes, you are right the navigation form is not user friendly and is not the ideal way to go. I did find a work around after trying different things so I do have it working but I will also watch the Parameter Value Video again. I watch his videos over and over because they are extremely helpful, and I learn a Lot.
Thanks again for your help.