In Marg Software there is option available to freeze data of sale, purchase and vouchers etc. which is used by user to usually freeze that data so that no changes or deletion can be done further. This results to freezing all the modules till the particular date. 

If in case any indication (as shown below) is appears at the time of modifying bill then it is showing because of that particular days or date defined in freeze data.

In order to remove the freeze day’s, the user needs to follow the given steps:

• Go to Masters > Passwords & Powers > Freeze data .

• A 'Freeze Data' window will appear.

• Then the user will remove the days which is defined in Auto freeze back date column for sale.

• Then remove defined days from 'Sale' option and then click on 'Accept'. 

After following the above steps, the user can resolve the error of Sale Freeze Upto which is appears while modifying the bill.