1998 GMC Yukon V8 Four Wheel Drive Automatic 130000 miles
The driver door will not open from the inside or the outside. The power locks and windows are working properly. The plastic molding around the outside handle has been cracked/loose for a while but had been working with no problems. When trying to unlock the door with a key, it appears that the lock on the inside only comes up halfway. Pulling the lock all the way up does not help though. Neither does unlocking with the power lock button. This vehicle is driven on the beach while fishing. Possibly a corrosion issue?
Actually it sounds like the linkage has either come loose or has broken. You need to remove the inner door panel to access the handle. Once you remove it, you will be able to access the linkage and the door handle.
Let me know what you find or if you have other questions.