I'm having some trouble filing a 1040NR with a Sch OI tax treaty in ProConnect Tax. Specifically, the amount for the tax treaty UK 20 for a client on an F1 student visa is showing on line 1k of the 1040NR but not reducing line 1a by that respective amount. I am also claiming the W-2 to claim the tax withholdings from that W-2. However, when I try to zero out box one from the W-2 input screen, I get a critical diagnostic.

I was wondering if you could provide some guidance on how to properly file this return and resolve this diagnostic issue. Thank you in advance for your help.