Default No mf1 found?

When I try to flash a rom on TWRP it says something about no mf1 found so it skips then it says failed and won't flash rom.
Anyone know why?
I'm new to the sIII

Sent from my SCH-I535 using xda app-developers app
Sent from my...DO THE HARLEM SHAKE! !@#$%
RAZRRRRR HD^