Hi, I have an iMac Pro connected to an external monitor (an Apple Cinema HD Display 23" for those interested). It was all working perfectly fine until yesterday. When I take the mouse to the bottom of the screen on one of the screens to invoke the dock the whole dock crashes. That makes it unclickable on the other screen, and I can't change space or CMD-Tab to switch apps (also no mission control or Dashboard or Launchpad). The only way to fix it is to kill the dock using Terminal. A few seconds later dock closes and restarts and all is fine until I invoke the Dock again on the second screen (either deliberately or accidentally). I've tried reconnecting the monitor and changing the arrangement, but it's all still the same. Anyone experienced this before, and does anyone know how to fix it? Thanks.