Hi ddenby! How are you scrolling up? Are you using a mouse with a physical scroll wheel, the arrow keys, or something else? Thanks!

I am using the mouse wheel when it happens. Is isn't predictable though.. Sometimes it happens and sometimes it doesn't.. (usually when I accidentally attempt to scroll beyond the upper bound of the page/tab. e.g. quickly scroll to the top). but again, not always.

Your mouse wheel might have a feature where you can click it to the side to go back in your web browser.

Try this for me; go to a webpage where you could go back (i.e. you've clicked a link in that tab so you have a history). Then, instead of rolling the mouse wheel up or down like usual, try pushing the whole wheel to the left. Does it feel like the mouse wheel "clicks" in that direction, and does your browser go back?

The mouse wheel sits pretty low on the mouse but I can get it to click if I press hard enough to the left or right, but no, it doesn't cause the browser to go to the previous page.

Hmm okay. Is it possible you're pressing down on the Alt key accidentally when you scroll? Alt + Scroll Wheel is a default shortcut for forward/back.

no, just the mouse.. Thanks for trying to help.

No problem! Unfortunately, I'm not sure what's going on here. My hunch is that this isn't a feature or bug of Firefox itself, but that something about your mouse or keyboard is accidentally triggering the Back action.

I'm afraid I'm not going to be able to be of much more help here. :( I hope you figure out what the problem is!

again, thanks for trying.

You might be holding down the Alt key while rotating the mouse wheel. There are specific actions defined to set what happens if you rotate the mouse wheel and hold down modifier keys like Alt or Ctrl or Shift.

• mousewheel.with_*.action
• mousewheel.with_alt.action = 2

You can disable an action by setting the related pref on the about:config page to 0 (zero).

0 means "Do nothing" 1 means "Scroll contents" 2 means "Go back or forward in the history" 3 means "Zoom in or out the contents"

You can open the about:config page via the location/address bar. You can accept the warning and click "I accept the risk!" to continue.

• http://kb.mozillazine.org/about:config

Thank you, but that was not the case... (see questions and answers to TimeSync1 above)

@ddenby they are trying to help with different setups here. I think they already read through the posting. How old is that mouse and when was the last time you cleaned it? What kinda mouse it it? It sounds more like a mouse hardware failure more than a Browser.

The mouse is fairly new. (only 4 or 5 mos/ use.. and.. I have cleaned it (bottom) a few times. I don't thinkit's the mouse. This hasn't happened with other browsers (Chrome, IE). If there isn't a software (FireFox bug) that's causing it then it would happen elsewhere.

I appreciate everyone's attempts to help with this but unless someone has some insight into FF's underlying code and/or control mechanisms, it is probably a dead issue.

Again thanks to all who have tried to help.

Separate Security Issue, please update your Flash 28.0 r0 by removing it with this tool : https://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html If you use it Reinstall with Flash Player Version: 30.0.0.154 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>

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 61.0.2 with a Full Version Installer

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

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