Seems to have a weird bug where it saved the tabs open when I set it up, so now every time I open firefox and unlock it it opens the same tabs I had when I added this extension. Strange.

It has been very useful since Mozilla stopped locking properly like it used to, and since then I’ve been searching for a way to do this, as the master password only partially protects passwords, not the browser at startup.
- But when I type the password and press enter, it doesn’t continue.
- After unlocking Browser Lock, remove all open tabs and the pin tabs
I am waiting and hope that you will make it the first browser lock for mozilla.

Edit: After so many years in Mozilla, I left to another because of this. Mozilla first add a browser lock and now it's the only one browser without this. I don't care about this master password, I never add passwords to browsers.
Edit 2: Message for the Developer:
"Your extension is extremely aggressive and causes Firefox to lose active tabs upon locking. It seems to interfere with Firefox’s session management or triggers an 'OOM' (Out Of Memory) state that forces the browser to unload tabs.
The only way I managed to fix this was by forcing Firefox to save the session every 300ms and disabling memory unloading. You should fix how the extension handles the browser state during the lock/unlock transition, as it currently wipes out the user's workspace.
about:config = browser.sessionstore.interval: 30!
browser.tabs.unloadOnLowMemory: false
browser.sessionstore.restore_on_demand: false
Fix your session handling!"