As Rukidn said there is a plate embedded in the deck. It's an aluminium plate. So likely someone tried to tighten it down and stripped the aluminum threads.
This is a somewhat difficult and labor intensive repair. Remove the rail, which may prove difficult as many of the machine screws may be seized and there is no good way to get penetrating oil on them. Look into a hammer actuated impact drive. This looks like a beefy screw driver that is made to rotate slightly when you hit it.
Impact driver - Wikipedia
Once you get the track removed and cleaned up you will have to asses the damage to embedded plate. As Rukidn said look at the Timeshert inserts. Basically you would drill the plate out to a larger hole, tap it and then screw in the threaded insert. This will leave you with good, new threads that you can use to put the track back down. You may find you need to repair several of the spots.
Then bed the track with Butyl Tape following Mainesail's article. Because of the threaded plate this is not a perfect use of Butyl. You will need to use a Qtip with mineral spirits to soften the buytl at each machine screw. I find in this application it's easier to apply the butyl to the deck than the hardware. And then do a very small cone on the bottom of the track on each screw. You have to be very careful not to get the butyl on the threads or in the holes for the machine screws. The butyl will jam in the threads and seize the screw.
Make sure you put a little Tef-Gel in each hole first so you can remove the track in the future if needed.
Good luck. If you take some pictures during this it would make a great tech article for Mainsheet.
Jesse
