Had this same problem.
My PA schedule UE was blank, $0.00 but I couldn't get rid of it.
I went back to the Federal form, selected Deductions & Credit and scrolled to the Employment Expenses, Job-Related Expenses section. This was showing $0 as I had answered all questions in this section as 'no' but it still created a $0 worksheet that must have been transferred over to my PA state form. If you click Update on the Job-Related Expenses you can delete the $0 entry (just don't go back through and answer 'no' to everything again).
Once I deleted this $0 entry on the Federal side, I could delete the PA Schedule UE. This is done by selecting View - Forms and then scrolling down the the PA forms and finding Schedule UE (which was highlighted as not complete). Once I selected this form I clicked in the box in the top right of the form to delete it.
After this I could successfully e-file.
