Error: bad argument #3 to '?' (torch.*Tensor expected, got nil)

[Alinahui]

Hi every one i am getting this error, can anybody please help to resolve this issue: Program 'lua' started in '/home/Alina/codes/captcha master' (pid: 7886). tput: No value for $TERM and no -T specified parsing file: dataset/ans.txt parsing done /opt/zbstudio/bin/linux/x64/lua: bad argument #3 to '?' (torch.*Tensor expected, got nil) stack traceback: [C]: at 0x7f9b6b7981b0 [C]: in function '__newindex' ./data.lua:43: in function 'loadY' ./data.lua:63: in function 'storeXY' /home/Alina/codes/captcha master/captcha.lua:12: in main chunk [C]: at 0x004054e8 Program completed in 0.08 seconds (pid: 7886).