Error no 3104 on e tds return

while trying to validate my tds return 26Q through RPU version 2.4 i am getting error message code 3104 for three lines under field name "By book entry/cash"

i have re entered the data again on these three lines, still the same error is being generated

i have kept the said coloumn blank for all the entries ,but error is being generated for three lines only,i.e one line for each challan