A possible cause is security software (firewall) that blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.

Remove all rules for Firefox from the permissions list in the firewall and let your firewall ask again for permission to get full unrestricted access to internet for Firefox and the plugin-container process and the updater process.

See:

• https://support.mozilla.com/kb/Server+not+found
• https://support.mozilla.com/kb/Firewalls

This does not seem to help. It seem to have something to do with too many images being loaded at once, and it just breaks down. I cannot enter some forums because of their forum images that don't load and then lock down. I cant enter pages with lost of images, beacuse firefox just freeze. It's the same thing that happens when I try load X tabs. Have they limited images loaded at once, in config? is there any way I can remove that limit?

Are you using Clear Recent History to clear data if you close Firefox?

• https://support.mozilla.com/kb/Clear+Recent+History

Are you using software like CCleaner?

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.com/kb/Safe+Mode

Yes, I am using CCleaner and have tried clear history data, but when I try reach any website like that again it crashes.

Does it help if you disable CCleaner for Firefox?

It is possible that there is a problem with the files sessionstore.js and sessionstore.bak in the Firefox Profile Folder.

Delete the files sessionstore.js [2] and sessionstore.bak in the Firefox Profile Folder.

• Help > Troubleshooting Information > Profile Directory: Open Containing Folder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

If you see files sessionstore-##.js with a number in the left part of the name like sessionstore-1.js then delete those as well.
Deleting sessionstore.js will cause App Tabs and Tab Groups and open and closed (undo) tabs to get lost, so you will have to create them again (make a note or bookmark them).

See also:

• [1] http://kb.mozillazine.org/Session_Restore
• [2] http://kb.mozillazine.org/sessionstore.js

I did the following;

Disabled cleaning for firefox looked up the location of mentioned files (Sessionstore-1.js and a few more, sessionstore.bak) Bookmarked open tabs closed firefox Removed mentioned files started up firefox and arrived with one page at firefox standard startup page tried to reach www.msn.se failed.

Thanks for the help though! Willing to try more things, I really wish to get this fixed. I have no idea why it simply will not load the images and just freezes :(

Does it help if you use this:

• Firefox/Tools > Options > General > Startup: "When Firefox Starts": "Show my windows and tabs from last time"

There should only be one sessionstore.js in the profile folder and not a file with a number it.
The presence of such a numbered file is an indication that other software prevented Firefox from replacing sessionstore.js with the temporary file with the number.

Well, I guess not, as I am currently using it? :/

I am also using Session Manager

Still does not work, any more suggestions? It seem to overload from X connections trying to reach me

Create a new profile as a test to check if your current profile is causing the problems.

See "Basic Troubleshooting: Make a new profile":

• https://support.mozilla.com/kb/Basic+Troubleshooting#w_8-make-a-new-profile

There may be extensions and plugins installed by default in a new profile, so check that in "Tools > Add-ons > Extensions & Plugins" in case there are still problems.

If that new profile works then you can transfer some files from the old profile to that new profile, but be careful not to copy corrupted files.

See:

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox