So today I updated my mid-2012 11" MBA from OS X Mavericks to OS X Yosemite 10.10.1 and I've been experiencing trackpad issues. Basically, all gestures except for scrolling, clicking, selecting and dragging have stopped working. Gestures for: - Mission control - Exposé - Launchpad - Swiping between fullscreen apps - Swipe from the right for Notification Center and widgets - Gesture to show desktop/hide open apps What still works: - Three finger drag and move - Scrolling - Clicking It was working right after the update. Then it started to get buggy. Launchpad gesture was the first to go away and now all of the aforementioned have stopped working. I'm sure that with a restart it would probably work but I can't right now since I'm backing up to my Time Capsule/Time Machine. (it needs to back up 20GB and it has already started so I don't feel like stopping the proces now seeing as there are workarounds for my problems.) Has anyone else experienced this?