Looks like ProSeries did an update to the Illinois Sched K-1 Worksheet yesterday. There is a checkbox for "Include on K-1-P(3)?" which is not flowing correctly. My client is an S Corp shareholder who owns 100% of the Illinois S Corp. He is an IL resident, so that checkbox should NOT be checked. But ProSeries is hard-coding the "X" and not allowing me to remove it. (Unless I override it which I shouldn't have to do).

This IL S Corp is NOT electing the new PTE election for 2021, so that checkbox on the K-1 worksheet should be blank and it should NOT be populated with an "X". When ProSeries made a programming change for the PTE election on the IL S Corp return, they messed up this checkbox. 

EDIT: IGNORE THIS - I NOTICED THAT THE SHAREHOLDER'S STATE OF RESIDENCY WAS "L" AND NOT "IL". THAT'S WHAT CAUSED THE ERROR.