> Firefox would pop up a vague message telling me that "one of your tabs" is causing an issue (not telling me which one) and then I would need to randomly close

> Firefox would pop up a vague message telling me that "one of your tabs" is causing an issue (not telling me which one) and then I would need to randomly close tabs to try and get things working properly again Did you have any addons installed? LastPass is a bit notorious for this, even the e10s-compatible version is quite bad.