My WordPress blog crashed when I tried updating it to the new Version 5.0. I swear I could hear a woman screaming in the background when I realized that everything stopped working. It also turned out to be way more difficult to recover than expected because I was running multi-site on it.
Gutenberg simply crashed everything
Basically, the new version of WordPress refused to play nice with the presumably outdated version of Gutenberg I have running on my semi-neglected blog. It crashed everything, including my other private sites I have running on this installation.