Here's a list of plugins known to cause problems and what to do.

Screet Chat x
Problem: Causes conflict with Sumo Search, and possibly may crash browsers in OSX Safari.
Solution: Screet uses an old build of firebase.js which is determined to be the culprit. A new update of Screet is being worked on as of this writing. Update your copy of Screet as soon as possible.

Page Builder Sandwich
Problem: Sumo Search hijacks typing during editing with Page Builder Sandwich and results in unwanted site searches.
Solution: A new update for Sumo Search is being worked on to mitigate this issue. For now, temporarily disable Sumo Search.