3251237 - Mass Data Entry copy pasting conflict-SAC

when entering data on an unbooked cell through mass data entry it isn't possible to copy by copy and pasting values on other cells:
Copying and pasting data from an unbooked cell is not supported because of possible data conflict.

SAP Analytic Designer

1- Open a Story 

2- Enable the Mass data entry

3- Write a value in an unbooked cell

4- Copy the written value in another unbooked cell 

Normal behavior 

underlying values cannot be copied from a cell that was originally NULL.

During Mass Data Entry, you can change a NULL cell to a data cell by entering a number into it. Even though it may look like a booked cell, it originally wasn't one so you won't be able to copy underlying values from the cell

Entering Multiple Values in a Table | SAP Help Portal

KBA , LOD-ANA-PL-DE , Data Entry and Mass Data Entry , Problem