Try to rename/remove the sessionstore.js file in the Firefox profile folder.

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

Location used for the main profile in "AppData\Roaming".

• C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile>\

"AppData" (XP: Application Data; Mac: ~/Library; Linux: ~/.mozilla) is a hidden folder.

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

As a bit more background to the above post: Firefox is trying to do a crash recovery but there is something wrong with the session history data. Removing the session history file(s), or hiding them from Firefox, will hopefully resolve that.

In addition to the sessionstore.js file -- which Firefox creates when it shuts down normally -- you may want to remove the backup files which Firefox uses when it did not shut down normally.

You can paste the following in the Start menu search box and press Enter to load it:

%APPDATA%\Mozilla\Firefox\Profiles

You should get a new window showing one or more semi-randomly-named folders.

Click into the one that looks most recently updated, and rename the sessionstore-backups folder to sessionstore-backups-old (you can right-click > Rename on the folder).

Then when you start Firefox, it should not find the files in that folder, but in case you need one of them for future reference, you'll still have them in the renamed folder.

I did what you instructed-renaming the file .......-old. When I opened firefox, I got the same response. Above the tab read, MozillaFirefox(not responding) and on the tab below was "aboutsessionrestore." This window was "frozen" and did not allow me to insert an address or navigate the page. I could not even close the window. I had to restart my computer. Please keep in mind that I am accessing firefox by using my other computer. Please help!! Thank you.

Sorry, that was in addition to renaming sessionstore.js if you found one.

Could you also look for any file named user.js at the main level of the profile folder? Sometimes that optional file will instruct Firefox to restore an earlier session overriding the normal behavior of loading the home page. Unless you created the file yourself, you probably can remove it.

Did not find a file "user.js." Just wondering if I can delete all of the firefox files, as I don;t need to save any info from them, and the reinstall firefox. Don;t need to save any prior history. Thank you

In that case, try:

Create a new Firefox profile

A new profile will have your system-installed plugins (e.g., Flash) and extensions (e.g., security suite toolbars), but no themes, other extensions, or other customizations. It also should have completely fresh settings databases and a fresh cache folder.

Exit Firefox and start up in the Profile Manager using Start > search box (or Run), type or paste the following and press Enter to run it:

firefox.exe -P

Don't delete anything here!

Any time you want to switch profiles, exit Firefox and return to this dialog.

Click the Create Profile button, assign a name like April2016, and skip the option to relocate the profile folder. After creating the profile, select it and start Firefox in that profile.

Will Firefox start?

If you do decide to look for old data, this article should help: Recover important data from an old profile.

Thank you so much. God bless!! Can't thank you enough. Bob