Steps to reproduce: 1st method -Enable e10s on latest Dev Edition -Visit a new sign-up form -Right click on password field to have last pass generate a password -Click "Accept" When looking at a form -Go to Lastpast launcher at top of browser -Click "Generate secure password" -Accept or Copy The browser will hang indefinitely.

What version of LastPass are you using?

I am using 3.2.42

There's a new version available at https://lastpass.com/ that works much better with e10s. The UI is quite different though so it hasn't been pushed out to all users yet. I think they want more testing and feedback.

Installing it from their site added it to my Safari and Chrome but it doesn't seem to install in any of my Firefox builds. It removed it from my browsers and is now nowhere to be found. (it's not even "just" disabled in add-ons) I'll try to resolve this again later.

Update: I was unable to install it via their website. It goes through the installer, restarts my browser and everything but it never shows up in it. I've re-installed it via AMO and disabled e10s in the meantime.

Not exactly related, but after fire-walling off Mozilla updates on all my computers, (angry at direction of Mozilla), I have come back to Mozilla to see if things going any better. I experienced the above problem, but even worse, not being able to login to websites even manually (without even using LastPass assistance..i.e the old type it in way). I guess after updating my computer from an old v38 up to a v46...Firefox just accepts the legacy Plug-Ins without signing (or it signs 'em)...but the problem is/was the old LastPass from back in v38 days, causes severe problems with the newer v46. Updating to Latest LastPass fixes all problems.

will have someone reach out to lastpass author on when version 4 can move from Beta - as that fixes e10s issues....billm, do you know a contact?

putting under main e10s-lastpass tracking bug - so we don't loose and test/close when Lastpass Beta version 4.2 (webextensions version) becomes released version. https://addons.mozilla.org/en-US/firefox/addon/lastpass-password-manager/versions/

Lastpass is now a webextension.