Permission error on pass-through php file

Creating a plugin and most of the functionality works. However, there is a time when I have a permission problem.

I click on my custom “create” button on a plugin admin page. That button (form) then calls a php file which processes the information and then should redirect to a new page. The problem is that whenever I click my “create” button, I get the “you do not have permission to access this page” error. This happens even if I just type in the url.

I even made a temp copy of my pass-through php file that only echo’s “hello.” I still get the permission error.

Help!