I decided I wanted to learn how to use Selenium with Jenkins so I installed the ChromeDriver and Selenium plugins on Jenkins 1.486. Immediately after doing so, my Jenkins nodes started displaying the "Connection was broken" error message from the master Jenkins instance. Checking the connection from the node itself, everything looks fine. The node appears to be connected, but the master thinks otherwise. I'll obviously have to to some trouble-shooting. For now, I removed the ChromeDriver plugin and my node connections are working again.