First of all, we have to understand that this is not an error, it is just an information message, it is informing you that the net profit you entered in "Question No. 40" and in "profit and loss report" is not matching.

Go into Reports > Balance Sheet Reports > Profit & Loss A/C
Check net profit in "profit and loss report "

Go into Audit > Tax Audit >New 3CD W.E.F 20/08/2018 >Question no 40
Check net profit in "Question No. 40"
Hope This Helps