Thunderbolt monitor Ethernet adapter causes network preferences pane to crash
I had this same issue (10.11.1). It was triggered in my case by plugging an ethernet cable into a 5k iMac that had previously only ever used WiFi. The network preferences pane would hang and com.apple.preference.network.remoteservice was shown as taking 100% CPU and "(not responding)" in Activity Monitor.

I tried deleting several network related files in /Library/Preferences but the one that seemed to do the trick was /Library/Preferences/SystemConfiguration/preferences.plist. Deleting that file and rebooting allowed me to load Network Preferences, and everything seems good now.