Hi TJB, Check this article Firefox starts automatically when I restart Windows to help prevent that from happening.

Start Firefox in Safe Mode {web link}

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

Next,

https://support.mozilla.org/en-US/kb/how-to-set-the-home-page

Type about:config<enter> in the address bar. If a warning screen comes up, press the I Accept the Risk button. At the top of the screen is a search bar. Type browser.startup.homepage

What is the value? Right-click and select Reset to restore its default value; about:home

Thanks for both replies. I did get the dialogue box which said 'Start in safe mode' and clicked on that. I still had to restart the computer to get rid of the numerous windows which were already open , each one was filled with tabs all labelled 'error' which could not be closed as they simply repopulated. It reminded me of those annoying pop up window tricks that you may have seen people play where window after window cascades across the screen, only in this case it was a new Firefox window which quickly filled with tabs.

For RobertJ, it wasn't that it was my previous window re-opening it was the fact that it was almost virus like in its behaviour, populating tab after tab after tab all called 'Error' and then when that window was full it opened another instance of the browser and continued tab after tab after tab....

Anyway. Thanks for both your inputs. A fresh start once more tonight with no issues has reassured me that it was simply a glitch.

You may have to rename/remove sessionstore.jsonlz4 in the profile folder to recover from those broken tabs. This file is only present when when Firefox is closed.

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.

• Help -> Troubleshooting Information -> Profile Folder/Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• https://support.mozilla.org/en-US/kb/Profiles

I'm sorry. I've tried to be polite in my responses. But not one person has yet actually appeared to have read and responded to the issue I had.

Let me try one last time.

I had an issue where upon start up my Firefox browser started up uncontrolled. It Opened multiple windows each window opened up uncounted numbers of tabs, all of those tabs were named 'ERROR'

When one window was full, another window cascaded across the screen. This behaviour continued. It did not stop. The Firefox help buttons did not help and the 'safe start' remedy did not help until I restarted my system.

It was not an instance of an old browser restarting upon a boot up.

Sorry, but your problem is new to us.

Do you have a website shortcut? Try to use it. Same problem?

Create a bat file to open Firefox using the -P option. Example: firefox.exe -P

This should open the Profile Manager. Same problem?

Did you at least try to remove sessionstore.jsonlz4 with Firefox closed ?

If that didn't had effect then you may have a problem with malware on your computer.

• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware