The click/tap function on my trackpad has been disabled. How do you rengage the function? I can't click on anything to select it. The icon moves around but can't click on application.

I managed to reactivate the click/tap function of the trackpad using voice over. You can start voice over by pressing cmd+fn+F5. There is a funny tutorial teaching you how to navigate your macbook by keystrokes. Took me quite a while but worked in the end! 🙂

press the pad with your 3 fingers ( long pressed) then it should work..enjoy!

Does the trackpad not physically depress and click at all, or does the click happen but have no effect?

If the trackpad can't be depressed enough to click, your battery may be swollen and pressing upward against the underside of the trackpad. Take the machine in for service immediately and ask to have it checked for battery swelling, an all-too-common failure mode for MBP batteries. If yours is swelling and isn't attended to quickly, it could break the trackpad or damage the bottom cover and/or the unibody chassis of the computer.

There is no way to disable clicking in the Trackpad prefpane. You can disable Tap to click, but physical clicking still works with that function disabled. If it doesn't work on your machine, I suspect your trackpad has a hardware fault.

No, I doubt that that is possible. Clicking is expected to work at all times. If it doesn't, take your machine in for service.

If you have access to a USB mouse, you might plug that in and see whether it works. It it does, that will both enable you to reactivate Tap to click and confirm that your trackpad is faulty.

The problem repeated after creating a new user account on my macbook. Only then I found out that in fact the lower part of the trackpad can be clicked like a key ... even with tap/clicking disabled. 😁