I was trying to get chromecast working from my thinkpad t420 laptop running Ubuntu 16.04 and ended up installing lots of packages in an attempt to get MkChromecast working. I didn't get it working, but I did end up freezing up my computer and needing to force a reboot. Upon restarting, I was unable to login. I reached a screen with the text:
Error cannot find command gfxmode.
Starting Linux [linux version]
However, it did not start linux after this text. Instead, my computer became unresponsive.

Luckily, I happened to have a live flash drive of Lubuntu so I started that up and ran the Boot-Repair tool. This didn't fix the problem (I tried rebooting after and it still froze up), but I did get a bit of information that I am not quite sure how to interpret: https://pastebin.com/fjlqfekg

If anyone has a solution, I would be very grateful! Thanks.