can not use LOSS_LESS mode

INVALID_PARAM will return ,when i create nvfbc object with loss_less mode or use "-lossless" in the nvfbc demo.
the sdk version is 2.3.7 final
the driver version is 354.13_grid_kepler_win8_win7_64bit_internation
the desktop system is win7_sp1

Does anyone have any ideas about this?

Do you have a Kepler Generation GPU? As this does not support lossless mode encoding.

thank u