That is where the issue is in sessions. as while your Win10 is asleep or locked Firefox is still updating the tabs that are in use and sites that send refresh out to browsers. You can get the gist of the issue from this URL and maybe make the changes of refresh tabs longer : https://www.servethehome.com/firefox-is-eating-your-ssd-here-is-how-to-fix-it/

I do not have a official thing on that. A (Copy/Paste the following in to URL search )( Session Manager ) Extension maybe the answer to this issue : https://addons.mozilla.org/en-US/firefox/extensions/

So copy/paste Session Manager + Tab Session Manager

Please update your Flash 27 Flash Player Version: 29.0.0.113 Current Version https://get.adobe.com/flashplayer/otherversions/ Step 1: Select Operating System Step 2: Select A Version (Firefox, . . . .) Note: Other software is offered in the download. <Windows Only>

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

Does your Windows "sleep" while it's locked or is it just sitting there waiting for you when you unlock the screen?

It's a little hard to picture how Firefox could become so confused. Do you use multiple resolutions? Some users have reported strange happenings when they have a higher-than-full-HD monitor and they run a game that switches the resolution to full HD.

As an attempted workaround:

Before locking the screen: Try a minimize all. Either Windows key + D or Windows key + M should do it.

For an off-screen window: Try right-clicking a window thumbnail above the Firefox Taskbar icon and choosing Maximize. That works on Windows 7, but I don't know about Windows 10.

No, my desktop computer is not set to sleep at any time. Both monitors are identical 1920x1080 except for one is connected by HDMI and the other is connected by DVI. I don't use full screen view in Firefox. I prefer to look at web pages as a 8.5x11 sheet of paper. I use the extra area for running other programs.

As I mentioned since is stall awake and is still updating the tabs that is the issue. It maybe having trouble moving the data since it is in a state of semi hibernation. Reduce the amount of tabs, change the refresh values or use a Session Manager

• https://addons.mozilla.org/en-US/firefox/extensions/

You can try this : 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/

Or it is your Profile : Make a new one and test ...:

• https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

If is your Profile :

• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile
• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

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

It just did it again! This time I had 1 window open with a dozen tabs Some were PDF files others were just pain web pages. Windows10 announced it would like to reboot to install updates. I let it proceed without closing anything. After I logged back in my Firefox window had shrunk to a small size off the top of the screen again. The only way to access it was use task manager to terminate it and then restart Firefox. Then I could relocate and re-expand the window but of course all of my open tabs were gone! Has anybody fixed this bug? My computer never had a chance to either hibernate or go to sleep this time.

Regarding your session:

Could you check whether either of these are available (not grayed out):

• "3-bar" menu button > Restore Previous Session
• (menu bar) History > Restore Previous Session

If they are grayed, check either:

• "Library" toolbar button > History > Recently Closed Windows (and within each restored window, Recently Closed Tabs)
• (menu bar) History > Recently Closed Windows (and within each restored window, Recently Closed Tabs)

I have my computer set to start Firefox when it boots. So the new session after the reboot was my home page and no other. Now that session is shrunk and off the screen. If I use the task bar to shut down Firefox it restarts with the same shrunken off the screen window. Only task manager ending session resets the saved location now the window is on the screen. Of course the last session was the home page session with no other tabs. Restore last session isn't grayed out but the last session is not what I wanted to recover because Firefox has been restarted twice.

Something is either corrupting the saved window size and location data or it's not being saved properly when Firefox is shut down by the OS.

I don't know what is happening to Firefox while Windows is sleeping. ???

You could consider changing your startup setting to

"When Firefox starts: Show your windows and tabs from last time"

That's near the top of the Options/Preferences page:

• Windows: "3-bar" menu button (or Tools menu) > Options
• Mac: "3-bar" menu button (or Firefox menu) > Preferences
• Linux: "3-bar" menu button (or Edit menu) > Preferences
• Any system: type or paste about:preferences into the address bar and press Enter/Return to load it

Here's another quirk with this failure. Win10 had another update and wanted to restart. I close Firefox window 2 then window 1. Then within 5 seconds told the OS to update and restart. When it came back the Firefox window was shrunken and off the top of the screen again. What does updating the OS have to do with Firefox loosing the last used window locations?

Hey, have you solved this problem?

I had same problem, and I have solved it: https://support.mozilla.org/hu/questions/1220103

Not really. Firefox still goes wacky when the OS updates. I shut down Firefox then allow the computer to update. Then after I log back in the Firefox is running like it is set to except for the window is as small as possible and off the top of the screen. I have to kill the Firefox and reopen it in order to see and resize the window. Happens every time the computer updates.

Are you at Windows 10 version 1803 yet ? Please Check in System --> About and if not please do this : https://www.microsoft.com/en-us/software-download/windows10 Will get rid of the updating and maybe be more stable.

Can also try another reinstall and this time : Profile : Make a new one and test ...:

• https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

If is your Profile :

• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile
• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox