Hi.

On my PC, in Firefox I usually download web pages and then read later offline. Today I opened a few webpages but FF kept freezing up. So I deleted a file called 'sessionstore.jsonlz4' in .mozilla. Then re-launched FF and now the web pages open fine. Is it safe to delete that file? The reason I decided to delete that file to solve this was because in the past, sometimes Firefox would open 2 instances at once - the solution was to delete a file called 'sessionstore.js' - the above file was almost the same in name - I know it was a different issue but I took a chance at fixing it.

Well, assuming this file was in /home/whatever your username is here/.mozilla/whatever.default or similar here/ then this is your browsing profile folder for Firefox, for your normal user account. Therefore you could create another browsing profile for Firefox, therefore it would be safe to delete that file I would imagine. Particularly given I don't see any such file on my system.

But you as far as I can see, do not mention which version of Firefox you have installed, or which distro though...

Hi jsbjsb001. I'm using FF 60.4.0esr (64-bit) on Debian 9 Stable.

I've got the same version of Firefox (and I'm using it right now), and it does also freeze up on me too. I've seen others report this as well, so it looks like a bug in Firefox, and therefore it's not just your system. I've found pressing the ALT key un-freezes it, being the keyboard combo to switch between running apps, being the ALT+TAB combo. But just pressing the ALT key clears it for me, as in unfreezes Firefox. Try that next time it freezes on you.

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I just saved this page as "complete webpage" in Firefox v. 60.4.0esr on Slackware 14.2 and was able to open it without issue. But it's not something I do commonly, so I admit that the test may not mean much.

Hi Frank. Sorry - I should have added that I save the pages with the Save Page WE addon. That way just a single file is saved.

I've since restored that 'sessionstore.jsonlz4' file and the issue has not returned.

I will try the Alt key trick if it happens again. Cheers jsbjsb001.

Hi jsbjsb001. It happened again today. There was a problem with 1 webpage that I had downloaded and opened in Firefox while offline - over a dozen other webpages posed no problen. I hit Alt but nothing changed - FF was frozen. A forced quit was the only fix I found.

Sorry for the late reply Linus, I've been busy.

Did you try the ALT+TAB combo as well?

If you did and it still didn't work then maybe it's a different problem. Therefore it's likely a problem with the Save Page WE addon, if that's what you're using when the freeze occurs.