Business financial forecasting spreadsheet found a problem formula (Very complicated spreadsheet)

I keep getting an error message, i want to know exactly what formulas are causing the problem, everything in the spreadsheet seems to be working fine but its coming up a lot.

Someone who maybe has a bit of business/ financial analysis coupled with excel sheet experience would probably help a bit better.

I am quite literate in understanding data, so this is not a massive job. Just identify the problem formula in case there is any, but understanding how all the numbers flow & work with the dash does help.