Cyclone IV Programmer Failed

Hi, i am trying to use Quartus 10.1 Programmer to transfer my code to the fpga (DE0-Nano) but i it says "Failed" all the time... i did the pin planner for the EP4CE6F17C6 using the ones from the DE0-Nano user manual,l but it uses EP4CE6F17C6N not EP4CE6F17C6, how can i solve this? Ty