You didn't say what Line number of Schedule C, Part II is the issue. You only said "building." So I'll take a guess. Is it Line 27b by any chance (Energy Efficient Commercial Building Deduction)? Here's a similar thread from last year. Read the entire thread, and see if you have the same scenario, and if the solution posted there by user @djkmann works for you. It worked for several others in that thread.
https://ttlc.intuit.com/community/taxes/discussion/intuit-programming-error-home-business-sch-c-line...
