So, you have a MAIN firmware what match with your phone's firmware version. E.g if your phone type is K810 and firmware version is R8BA024 GENERIC, then you need this MAIN firmware K810_R8BA024_MAIN_GENERIC_SM_RED52.mbn. Copy the MAIN firmware to [SETool2 Lite v1.11 folder]\qamaker\ folder. Select the MAIN firmware(*.mbn file) and drag it(drag and drop operation) to qamaker.exe