please check if the new file has any fields which is null value in the field ur moving . dacimal data error comes in multiple senarios . when the invalid decimal value is moved to a decimal or numeric field or a nul value is in the nummeric field and is manipulated. so try this code before ur move statement
IF FILE-VARIABLE IS NOT NUMERIC
MOVE ZERO TO WSAA-X
Here wsaa-x is the pic x(03) variable and file variable is the field u get from new file.