Motion tracking stops at a certain frame before the end of the shot I have 7223 frames to track, I set my track mark it only goes to 762 then stops. Even though it does not do that usual thing when it loses it mark, I still reset the mark, then go one frame at a time, and it is not tracking it. 
as you see it does not lose the track it just stops and will not go any further.



Any ideas why?
If the tracker is very close to the edge, the automatic tracking will stop. It cannot keep tracking if there are no pixels to fill the tracked area.
Either offset the marker (GG) or create a new one and join both, else you can manually position the tracker for any given frame.