Have a monitor dock (https://www.amazon.com/Dell-Monitor-Adapter-450-AEUO-4W2HW/dp/B01C8PHWQY) that I use to plug displays in to. After updating to Ubuntu 17.10 plugging in to either display causes the display server to crash and stop responding. Usually with just blank screen, sometimes just becoming unresponsive.

Occurs with Unity/Ubuntu X-org and Wayland.

Not sure if there is anything I can do to make it more stable anyone have any troubleshooting tips.

EDIT: I got 3 monitors working again but I won't be marking as answered because my doc issues still persist.

I was able to get 1 monitor working by setting the primary laptops display to be 1920x1080. Plugging in the first monitor to the doc's hdmi port and then setting its resolution to 1080 as well. Finally the third one would work.

TLDR change to 1080 before plugging them in.