MTS or rather HD Video may require some plugin or very current version. I don't keep track of the Avid product line so the fastest answer will be from Avid. Seems you would expect answers for the price of this software!
I purchased a sony HDR CX160 camera to record soccer games. I then purchased Avid studio to edit video. I imported the MTS files to Avid but when it plays it only shows caartoon of exclamation mark. The icons show a lock, as if trying to tell me the video file is protected. The file plays sound but video only shows cartoon exclamation point. Help please.