If a latch would not snatch well, test for an obstruction withinside the tracks that can be maintaining the sash from final fully. You also can look at the weatherstripping, that may on occasion wad up and make final the window tough. You can be capable of regulate the latch with the aid of using loosening a screw, transferring the latch, and retightening the screw. If this nonetheless would not paintings, you will want to update it.