I have been trying to import stemed files into Ableton Live. Ableton doesn't seem to be able to use the files. I noticed that the stem files are saved in a MP4 format. I am not sure what I am doing wrong but I noticed that Traktor Pro 4 takes exclusive control of my sound card and will not let any other audio play when it is open. I have looked at settings in Traktor but do not see any way for it to share the resources. I must be missing something. any help would be much appreciated.