Try to open a new window and see if that new window works.

If that works then close the not working window and possibly drag tabs that you want to keep over to the new window.

You can also try to elete the sessionstore.js file and possible sessionstore-##.js files with a number and sessionstore.bak in the Firefox profile folder.

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
• http://kb.mozillazine.org/Profile_folder_-_Firefox
• http://kb.mozillazine.org/Multiple_profile_files_created

Deleting sessionstore.js will cause App Tabs and Tab Groups and open and closed (undo) tabs to get lost and you will have to recreate them (make a note or bookmark them if possible).

• http://kb.mozillazine.org/Session_Restore

Your Shockwave Flash plugin is out of date.

Update It

Updating it may fix your issue.

How do you have Firefox 25? Only 22 has been released.

@ComputerWhiz: Well I've been using Nightly instead of regular firefox, so I guess that is it.

I switched over to regular FF and it seems to be working fine, so I think I'll just be using this for now. If I feel like going back to Nightly I'll try out your guys' suggestions, thanks.

You should always install Nightly and Aurora development builds alongside of the regular release version, so you can switch to the release version in case of problems.
A Nightly build can fail at any time or can suffer from other issues, so you need some experience and expertise to deal with such issues.

Create a new profile exclusively for each Firefox version.
Create a desktop shortcut with -P "profile" appended to the target to launch each Firefox version with its own profile.

• http://kb.mozillazine.org/Testing_pre-release_versions
• http://kb.mozillazine.org/Profile_Manager#Creating_a_new_profile

• http://kb.mozillazine.org/Shortcut_to_a_specific_profile
• http://kb.mozillazine.org/Using_multiple_profiles_-_Firefox
• http://kb.mozillazine.org/Bypassing_the_Profile_Manager

Nightly is not a fully functional browser. It is supposed to be for testing purposes only because it still has some stability issues.

This has been reported by Firefox 25 users running the bbLean shell (Blackbox for Windows) on Windows 8, as discussed in this thread: Tabs will not close no matter what, even in safe mode. No idea whether that is relevant to your configuration.

This may be related to Tab Mix Plus, though I have no pinpointed which feature exactly. I deactivated it and was able to restore my session prior to installing Aurora, and everything's back to normal.

I have this problem too. I close all the tabs and close Firefox. Then when I open Firefox again all the tabs (now around 10) appear. If I go to File on Firefox and click on close Firefox they still reappear. What a nightmare - the slow my computer down. Do I need a different Browser or is there and answer to this Problem?

Hi rebeccaspeer10, you posted the same comment in 3 different threads and actually none of them matches your description. If the following is not helpful, please start a new question using this link (scroll down past the suggestions to continue with the form, which has a series of 3 screens): https://support.mozilla.org/en-US/questions/new/desktop/fix-problems

Have you tried shutting down Firefox using "Exit" or "Quit" instead of Close?

Firefox will automatically restore your previous session if it thinks it crashed (i.e., it did not shut down correctly). To see whether that is happening, you can change a setting so that instead of automatically restoring the session, Firefox display a list of windows and tabs. If you see that at startup, it's a sure sign that Firefox did not shut down correctly and we can focus on figuring out why that's happening.

Here's how to make the change:

(1) In a new tab, type or paste about:config in the address bar and press Enter. Click the button promising to be careful.

(2) In the search box in that tab, type or paste sessions and pause while the list is filtered

(3) Double-click browser.sessionstore.max_resumed_crashes and change the 1 to a 0 (a zero) and OK that.

(4) You can close this tab now.