E1 Sales update issue - Discount Date Invalid or Missing

Hi,

I have one sales orders with line No 1.000 splitted into 1.000 & 1.100 with line status 580 -620. Invoice date against both the lines are different. The line number 1.1 got correctly sales updated. But in case of any Line No 1.000, i am getting the error in work center as below -

Date : 11/07/2016
Subject : Error: Discount Date Invalid or Missing
CAUSE . . . . The Discount Date field is invalid for one of the following
reasons: MONTH is not valid (must be between 1 and 12), or DAY
is not valid (must be between 1 and 31, but must also be valid
for the month), or YEAR is not valid (must be between 00 and 99),