Ive tried loads of ways, I can’t seem to get the track back from any of the many saves I’ve made. just seems a combination of what ever I did is effecting all the group tracks of this one song, I image the saving has some global attributes within a project so when that goes it all crashes. I was having a video driver issue & the problem with all the video exe and dll in cubase causing it not to close properly so i reckon the file got corrupted when shutting down cubase. weird it affected all the backups too ;/
but yes the workaround is something to extract tracks from corrupt .cpr files . least now i don’t have to start totally from the beginning Urgh.