Here, the major problems are presented, along with solutions.
Problem 1: Door Gets Stuck
Solution: The reason for this problem is mostly bad roller wheels. To save cost, roller wheels of your sliding screen patio door are generally made up of substandard plastic. The plastic is generally lightweight and also fragile.
Most problems with home appliances occur because the manufacturer generally compromises quality, for bringing down the cost of the appliance. Another problem is that generally, all these products are not field tested. That is, they generally do not undergo stress tests or a quality check.
The material used is not tested, for how it will respond to changing weather conditions. So, what usually happens, is that under large swings of temperature, the plastic becomes brittle and breaks down under applied force.
Check if the rollers are broken down this way. If they are indeed broken, then you are dragging the door through the slot, instead of rolling it. That is why, the door gets stuck, due to friction.
The solution to this problem is simple enough. The replacement of the rollers is not that difficult or expensive. These parts are easily available in all hardware stores. Buy some new rollers. Go for better quality rollers and make sure that they have identical brackets, as the old ones.
Get the screen out of the way first. Then, remove the old rollers, by detaching their brackets with a screw driver. Put the new ones in place and your door is back to its old smooth sliding self.
Other reason for the door getting stuck may be dust or dirt, in the roller slots, accumulated over time. In this case too, remove the sliding door, clean the dust with the vacuum cleaner, or just dust it off with a brush. Once the slot channel is clean, your door should slide easily.
Problem 2: Door Keeps Falling Out
Solution: The reason might be that the door is too damn short and that is why it keeps on getting dislodged from slots, if there is any vertical movement, instead of horizontal.
Don't worry, your sliding door is not doomed. All of them, come with a height adjustment facility. The height adjustment of the door is done by using a screw. The adjustable screws located at the top and bottom of the door do the trick. Just loosen the screws and adjust the height of the door, as you want.
These were two major problems that you could encounter, along with their solutions.