Error! document details pertaining to previous financial year cannot be added/amended now

pl clarify the following query;

one of our vendor filed wrong Invoices , dates, amounts also for the year 2017-18.

recently I advised to make CN for entire wrong invoices submitted by you and same month re-submit the correct invoices in B2B area, while re entering invoices in B2B , the above error appearing.

already GSTR9 due date is extended upto Aug-19 ending. why this error coming in gst portal.

pl advice, any remedy is there for the above problem.