When a door latch wont catch, its because the latch doesnt align with the hole in the strike plate. Sometimes you can clearly see the misalignment. If not, do the lipstick test. Smear lipstick on ...

A few weeks ago, the latch in my car door got stuck, blocking the door from closing. After a few crude attempts at jostling it, I knew it was time to purchase a silicone spray to lubricate it.