What you are seeing is either an input error or, more likely, a programming error (the latter since others have mentioned this exact error in the past).
You can try to troubleshoot the error by entering Forms Mode and determining whether anything is highlighted in red on the forms (particularly, the worksheets or Schedule K of From 1065) but you might be better off by simply contacting Support using the link below.
https://ttlc.intuit.com/community/using-turbotax/help/what-is-the-turbotax-phone-number/00/25632
