In our sales Quotation we have Plant ,area manager and few more partner as mandatory at 'Parties Involve' block.
so If user didn't enter plant,etc it will show error and not allow save on that quotation,
but from yesterday this is showing error but allowing save.
This is happening with Parties involved Only, Rest of The fields Validation working fine.
i.e.(If i do not enter any header level mandatory field it i will show error and not allow save).

please suggest me what i am suppose to do.
Note : i moved one development after that only this is happening.
My development is not new it's just one line change in previous working implementation of order_save badi.