An outstanding solution for little room problems, as with closets or doorways, is the sliding door. Two paneled doors that slip past each other are called bypass doors. Frequently they are used to span wide closet doorways.
Doors that are fixed in place, derailed, or leave space at the bottom can be attributed to a hardware hitch. The first thing on the list to check out is the roller brackets. Test each bracket by waggling one while keeping the others down. The screws of any slack brackets should be tightened.
If you can't pinpoint the wobbly bracket, just detach the door completely. The first thing you should take out is the guides. Take the screws off and keep the guides around. If any are bent or broken, they should probably be replaced with new ones, available at hardware stores. Bent metal guides can be corrected with pliers.
Firmly get a hold of one side of the outer door, while someone helps with the other side. Working together, tilts the door so that the bottom rises away from the inner door. At once, push up. On an adjacent wall, park the door.
In the same fashion, disengage the other door. Don't worry if this doesn't work, because you can try lining the door up with the openings along the track. This way, you can tighten all the screws without breaking a sweat. Don't sweat it if the screw openings have broadened, because you can always just buy bigger screws.
Turn the procedure around, and you have installation instructions. Once installed, they should be suspended at a level angle. Fix in place the floor guides once more, making sure that the doors are free to glide past each other. I'm sure you've seen pleated doors suspended from a single overhead track, and these are called bifold or accordion doors. Panels are pinned down by roller brackets or short spindles along the channels.
Getting this kind of door off involves taking out the spindles and then pushing up the door on the same side as the pins. In sync, push up the bottom from the floor. The spindles should be spotless before the door can be put back in place. Matching movements are done on the channel interior.