Had you done this yet? Type about:config in the address bar and Enter. Find the preference toolkit.legacyUserProfileCustomizations.stylesheets and set it to "true".

This site keeps up with changes to the code: https://www.userchrome.org/what-is-userchrome-css.html#movetabbar

I changed the value to TRUE and restarted FF, but it's still the same.

I looked at the file you linked to. Wow! I'm not sure I really understand everything that's in there.

I'm beginning to think I should just go back to 71 and stay there. The more FF is "improved", the more frustrating it gets.

Try the code I posted in this reply

• https://support.mozilla.org/en-US/questions/1276985#answer-1280813

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* only needed once */

/* TABS: on bottom - code for Firefox 66-73 */
#navigator-toolbox toolbar:not(#nav-bar):not(#toolbar-menubar) {-moz-box-ordinal-group:10}
#TabsToolbar {-moz-box-ordinal-group:1000!important}

#TabsToolbar {
  position: absolute !important;
  bottom: 0 !important;
  width: 100vw !important;
  display: block !important;
}

#tabbrowser-tabs {
  width: 100vw !important;
}

/* navigator-toolbox - padding */
*|*:root:not([chromehidden*="toolbar"]) #navigator-toolbox {
  padding-bottom: calc(var(--tab-min-height) + 0px) !important; /*adjust*/
}

/* TabsToolbar with menubar and titlebar hidden */
*|*:root[tabsintitlebar]:not([inFullscreen="true"]):not([sizemode="maximized"])
 #toolbar-menubar[autohide="true"] ~ #TabsToolbar{
  bottom: var(--tab-min-height) !important;
  padding-top: calc(var(--tab-min-height) - 22px) !important; /*adjust*/
}

/* TABS: height */
*|*:root {
 --tab-toolbar-navbar-overlap: 0px !important;
 --tab-min-height: 33px !important; /* adjust to suit your needs */
 --tab-min-width:  80px !important; /* adjust to suit your needs */
}

#TabsToolbar {
  height: var(--tab-min-height) !important;
  margin-bottom: 0px !important;
  box-shadow: ThreeDShadow 0 -1px inset, -moz-dialog 0 1px !important; /* omit */
  background-color: var(--toolbar-bgcolor) !important;
  color: var(--toolbar-color) !important;
}

#tabbrowser-tabs,
#tabbrowser-tabs > .tabbrowser-arrowscrollbox,
.tabbrowser-tabs[positionpinnedtabs] > .tabbrowser-tab[pinned] {
  min-height: var(--tab-min-height) !important;
  max-height: var(--tab-min-height) !important;
}

/* drag space */
.titlebar-spacer[type="pre-tabs"],
.titlebar-spacer[type="post-tabs"] {
  width: 40px;
}

/* Override vertical shifts when moving a tab */
#navigator-toolbox[movingtab] > #titlebar > #TabsToolbar {
  padding-bottom: unset !important;
}
#navigator-toolbox[movingtab] #tabbrowser-tabs {
  padding-bottom: unset !important;
  margin-bottom: unset !important;
}
#navigator-toolbox[movingtab] > #nav-bar {
  margin-top: unset !important;
}

/* hide window-controls */
#TabsToolbar #window-controls {display:none!important;}

/* move caption buttons to right end of Tab bar with menu bar and title bar hidden */
*|*:root[tabsintitlebar]:not([inFullscreen="true"])
 #toolbar-menubar[autohide="true"] ~ #TabsToolbar
 .titlebar-buttonbox-container {
  position: fixed !important;
  display: block !important;
  right: 0 !important;
  top: calc(6px + var(--tab-min-height)) !important; /*adjust*/
  visibility: visible !important;
}

*|*:root[tabsintitlebar]:not([inFullscreen="true"])
 #toolbar-menubar[autohide="true"] ~  #TabsToolbar {
   padding-right: 100px !important; /*adjust*/
}

Tried just about everything on the web for userChrome.css but nothing works. Bloody Mozilla have to come up with a simple solutions or make the default as tabs on bottom.

Hi malaus1

Is userChrome.css working at all?

In Firefox 69 and later you need to set this pref to true on the about:config page to enable userChrome.css and userContent.css in the chrome folder.

• toolkit.legacyUserProfileCustomizations.stylesheets = true

See:

• https://www.userchrome.org/firefox-changes-userchrome-css.html

The above posted code should at least move the Tab bar to the down position.

Yep. Tried everything suggested including the reset to true. Nothing changes so have no idea if it even knows if userChrome.css exists.

Can you post the full file path to userChrome.css to verify that the file is in the correct location (chrome folder in the profile folder) ?

Did you verify that the file is a CSS file and not a text file with a possible hidden .txt file extension (userChrome.css.css or userChrome.css.txt) ?

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: Open Folder; Linux: Open Directory; Mac: Show in Finder
• https://support.mozilla.org/en-US/kb/Profiles

The bloody thing was working fine until the last update to FF so all should be good. Heres the path C:\Users\Mal\AppData\Roaming\Mozilla\Firefox\Profiles\chrome and the image is what is in the Chrome folder showing some older files renamed to exclude them.

That is the wrong location:

• C:\Users\Mal\AppData\Roaming\Mozilla\Firefox\Profiles\chrome

You should create the chrome folder within the actual profile folder with the random name (xxxxxxxx.default-release).

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

What is the extra <profile> supposed to be? I assume it's the (xxxxxxxx.default-release) you refer to which just confused me, and why did it work before? The Chrome folder is definitaly in the Profile folder so do I create another folder of some sort? Excuse my delayed replies - I'm travelling at the moment.

The <profile> indeed refers to an actual profile folder inside \Profiles with a name like xxxxxxxx.default-release

Your mentioning C:\Users\Mal\AppData\Roaming\Mozilla\Firefox\Profiles\chrome suggests \chrome is in the wrong directory.

So, C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\xxxxxxxx.default-release\chrome\userChrome.css.

Further, it must be in the correct user profile folder, the one which you actually use, which is loaded by default when Firefox starts.

Typing about:profiles in the address bar and Enter will show which is currently the default profile in use.

That worked. You're legends Corel & cranky goat. Many thanks. Now all that needs gto be done is to pressure Mozilla to develop a simple fix for the next update ballsup.

Fantastic!

Just be aware that FF 73 is out soon, and that the chrome code does frequently change while Firefox is yet going through a fairly major changes.

The code I posted above still works for me in 73 (beta RC; about to be released) and 74 (Nightly build) with and without @namespace line.

Good to know in advance. Thanks, cor-el.

Probably won't update for a long while. Not until Mozilla provides a fix. Have to spend too much time restoring my preferences.