Just take off your door panels carefully, and follow the rods from the door latch to your inside door opening handle. The rod could have fallen off, a clip could have come off, or the metal on the handle where the rod attatches to could have broken. As the other guy said, it'll be obvious to you when you take off the panel and look for yourself. Not a hard job. While you're poking around in there, educate yourself a little by operating the outside door handle, the lock, the inside door handle while looking inside the door. It's interesting to see how the whole operation works.....and as a side point, lube all your moving parts with a little white grease while you're at it.
My outside door handle used to rattle a lot, so I took out the rod, bent it a little to shorten the length, then put it back on.....now have a nice, tight, quiet door handle when I shut the door.
Bruce '87 Grand National