This is due to the un matched table control lines.
the problem can be resolved as :
in the screen 100 in PBO describe the internal table to get the no of lines in the internal table that you want to display and assign the number of lines in to the table control lines.
this issue will be solved.
data: wrk_line_count type i length 3. "as per records
DESCRIBE TABLE it_1000 LINES wrk_line_count.
"assume your table control name is "TCTRL_1000".
TCTRL_1000-lines = wrk_line_count.