I've discovered that if I use a concatenate inside a vlookup, I get an error
message whenever I try to save the file. "Excel cannot complete this task
with available resources. Choose less data or close other applications". I
know that this is NOT the case because I can reboot, open nothing but excel
and get the same message.

If I delete this formula, I can save the file without the error message.

Any suggestions?

=VLOOKUP(CONCATENATE(A36,C32),'[Division Raw Data.xls]Adjusted OH by
Div'!$E:$F,2,FALSE)