I am using the following formula to sum two fields. ='First Details'!D178+'Second Details'!D178 This is summing two mortgage payments (first and second mortgage).

To the extent it's important, the formulas from 'First Details' D178 and 'Second Details' D178 are:

'First Details' D178==IF(C177="","",IF(+C177-E177>0,+$C$7,""))
'Second Details' D178==IF(C177="","",IF(+C177-E177>0,+C177-E177,""))

Everything works fine, until the second mortgage is paid off (around year 14) and there is zero payment due (loan is paid off). I get a #VALUE! error.

Any help for this newbie greatly appreciated! To put my newbiness in context, this is really just a modification of a downloaded Excel template. I didn't write the formulas on 'First Details' or 'Second Details' myself.

Thanks!