nvenc scale_npp causes FFmpeg to fail to launch HLS nginx

After updating my graphics card from a 680 to a 1650, I am now able to encode multiple bitrates of my HLS stream using NVENC. However, I am stumped with the following issue, if I attempt to add the argument for scaling -vf scale_npp=1280:720, FFmpeg fails to launch.

exec ffmpeg -y -vsync 0 -hwaccel cuda -hwaccel_output_format cuda -i rtmp://localhost/livestream/$name -c:a copy -c:v h264_nvenc -cbr true – b:v 1000k -vf scale_npp=960:540 -f flv rtmp://localhost/adapthls/$name_mid