djm 900srt firmware problem

my original issue is distortion when i try to record with my mixer. tried updating to serato dj pro and still have the same problem. i downloaded the new driver that worked fine, however it wont let me download the firmware to my mixer. it gets stuck on the firmware update screen after i hit start. i only says waiting for djm 900 connection. ive tried too many times to count haha. i have a macbook pro using a mac ethernet adapter so that shouldnt be the problem. i also checked my system setting and made sure the cable is enabled.