Vlookup index function error

[macro12]

Hi! I am having trouble with the formula in Column B:

=IFERROR(INDEX('By Task Order'!$B$1:$B$200,AGGREGATE(15,6,ROW('By Task Order'!$C$1:$C$200)/(VLOOKUP(INDEX($A$1:A3,MATCH(1,(-(ISNUMBER($A$1:A3))))),'By Task Order'!A:C,3,0)='By Task Order'!$C$1:$C$200),ROW()-(((MATCH(2,(1/($B$1:B3=""))))))-1)),"")

It won't pull all the rows for the specific employee and I can't figure out the reason, e.g. row 289. It happens quite frequently. Please help!