How to bring back multi-touch gestures after it crashes without reboot?

Solution 1:

Run the command killall Dock in Terminal.

In my case, only Mission Control gestures had stopped working (three finger swipe left/right to switch spaces, three finger swipe up for overview, mission control etc).

Solution 2:

By my experience, multi-touch crashes on a per-app basis. I could quit the app and relaunch it, and gestures would be back.

Apparently, sleeping the display and then waking up the system again will bring back crippled gesture. You can click button to do that, or just close the lid, or use terminal:

pmset displaysleepnow; sleep 5; caffeinate -u -t 1

After one second of black screen, gestures are back.

(P.S.: I'm answering my question here, so if it works for you, upvote and I will mark it as accepted)

Solution 3:

Hit the same issue. Found this old thread, where user frimp advises to press power button and let MBP sleep for a while, some 5-10 seconds is enough. Then wake it up — gestures are back.
Further search shows this issue is quite old, at least since mid 2012.

Though I would really like to get this fixed permanently…

Solution 4:

I found a faster solution. In settings → trackpad, disable all scroll and zoom gestures, then reenable them. The trackpad should start working again almost immediately (at least it did when I tried it).