Check whether the door is loose, sagging, sticking, torn, or not latching
Tighten all hinge screws
Replace stripped screws with longer screws
Adjust or replace the hinges if the door sags
Trim the bottom or side edge if the door rubs the frame
Clean the track and remove dirt or debris
Lubricate the rollers or track if the door is sliding poorly
Replace broken rollers or wheels
Tighten or replace the handle and latch hardware
Realign the latch so it catches properly
Patch small screen holes with a screen repair kit
Replace the screen mesh if it is badly torn
Replace damaged spline if the screen is loose
Straighten or replace bent frame sections
Reinstall the door if it is off the track or out of square
Test the door several times after each repair