That depends on what is wrong with it. If the missing liner is the problem sort out who the manufacturer is and get a new one.
Most of the time it can be stretched and reattached. It takes a little time and you may think it is invane but keep trying.
Fill it with water so skateboarders quit using it.
Pool supply stores carry patch kits that you can place on the liner underwater. They are cheap and work pretty good hope this helps!
no