usb external soundcard not working on imac osx10.6.8
Hi ,I'm trying to record music and get a soundcard- Native Instruments Komplete Audio 6 working but message says "no native instruments usb device connected". I've tried different usb ports to no avail.The manual says it will only work with usb 2 and according to my IMac specs it says usb 2, but no signal is coming through. The recording software is Cubase Le 5. Any help would be appreciated.
iMac, Mac OS X (10.6.8)