Nuuk said

I have also had the slowness and freezing problems with Quantum

Start Firefox in Safe Mode {web link} by holding down the <Shift> (Mac=Options) key, and then starting Firefox.

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

https://support.mozilla.org/kb/Firefox+is+already+running+but+is+not+responding

https://support.mozilla.org/en-US/kb/firefox-slow-how-make-it-faster

https://support.mozilla.org/en-US/kb/firefox-uses-too-many-cpu-resources-how-fix

https://support.mozilla.org/en-US/kb/firefox-uses-too-much-memory-ram

https://support.mozilla.org/en-US/kb/firefox-hangs-or-not-responding

But I have another odd issue where I open my saved tabs but the page shown is one from a past session

https://support.mozilla.org/en-US/kb/changes-toolbars-and-window-sizes-are-not-saved You may have corrupt xulstore.json or Localstore.rdf file.

Close Firefox. Open your file browser to this hidden location:

• Mac: *~/Library/Application Support/Firefox/Profiles
• Linux: *~/.mozilla/firefox/Profiles
• Windows: %AppData%\Mozilla\Firefox\Profiles
• *C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles
• Windows XP: C:\Documents and Settings\<user>\Application Data
  \Mozilla\Firefox\Profiles\

Search for the above files. Then rename or delete them. Restart Firefox.

No, it didn't happen when I restarted in Safe Mode, but then it doesn't always happen anyway, just from time to time.

Check the Browser console to see, if there any session-related errors (like this below, for instance).

 Could not write session state file  Object { operation: "move", path: 
"C:\Users\user\AppData\Roaming\Mozilla\Firefox\Profiles\7w701c2s.default\sessionstore-backups\recovery.jsonlz4", 
winLastError: 5, stack: "", fileName: "(unknown module)", lineNumber: undefined } SessionFile.jsm:396

OK, I will have to wait until the problem occurs again, and then I will check the Browser Console.

You have to check the Console before the problem occurs. For instance before closing Firefox. PS. I use to have this issue, but it was fixed in version 59.

TyDraniu said

You have to check the Console before the problem occurs. For instance before closing Firefox. PS. I use to have this issue, but it was fixed in version 59.

Ah - OK, I will try and remember to check each time that I close Firefox. I also have v59.02 so hopefully the problem has been dealt with. I will report back here if the problem occurs again, or after a week if it doesn't.

I think that I have found the reason for the changed tabs. Firefox is sometimes not shutting down, and I am forced to use the Task manager to close it. It appears that after I do that, I get the problem with the tabs.

So it looks as though my problem is the slowness of Firefox, and it not wanting to shut down occasionally.

Hi, please : uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files , C:\Program Files(x86) & C:\ProgramData Then restart system. Then run Windows Disk Cleanup. (Note: This should be Pinned and run Weekly, If never done below expect 10's of gig's) Then run it again and click the button that says Cleanup System Files. Note: your Firefox Profile is saved. But you should make a back up before you do :

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles
• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer

Reinstall with Current Release Firefox 59.0.2 with a Full Version Installer

• https://www.mozilla.org/firefox/all/

Please let us know if this solved your issue or if need further assistance.

OK, I have followed those instruction to the letter BUT - my passwords will not restore from the file that I backed up on my Desktop. Any suggestions please?

For some reason when restoring tabs in the bookmarks panel, it doesn't show the bookmarks imported, but I am pleased to say that when I go to the menu, and select bookmarks, all are now restored.

I will report back on how Firefox runs now.

I am very sorry to say that Firefox is even worse after the re-install.

Opening a link in a new tab only works sometimes. Switching to a different tab results in a blank screen that I can't do anything with.

Closing down sometimes requires the Task Manager.

And it is still slow.

While typing in something it will often have a delay of several seconds before displaying what I have type.

How could Quantum work so well when I first installed it, and now be reduced to this?

Things have settled down. Opening a link in a new tab now appears to work OK. And generally, speed is OK.

But I still have an issue where I open up Firefox, and find the odd tab has reverted to a previous page, rather than the one that was open when I last closed Firefox.