So I have the following Sumif formula working and giving the proper result.
=SUMIF([Business Unit]891:[Business Unit]900, [Business Unit]868, [Implemented FY18 (CUR)]891:[Implemented FY18 (CUR)]900)
The problem is the range isn't big enough and if I extent the range to beyond 900 rows I get the Unparseable error message.
I haven't been able to figure out what is causing the problem and I need to add 300 rows to the range.