Are you using an extension or code in userChrome.css to place the Tab at the bottom on the navigator toolbox?

Thanks for the quick response but it just confuses me. I don't believe I'm "using an extension or code..." because I don't know what this means. Also, what is the "Navigator toolbox"?

I'm sorry if I gave you the impression that I'm really knowledgeable about this stuff. Actually, I'm just a really old guy who likes the Bookmarks Toolbar below the Address Bar and thought there must be and easy way to put it there permanently.

Firefox would normally place the Bookmarks Toolbar below the Navigation Toolbar. If that isn't the case then something is interfering.

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Appearance
• do NOT click the "Refresh Firefox" button on the Safe Mode start window
• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

Can you attach a screenshot?

• https://support.mozilla.org/en-US/kb/how-do-i-create-screenshot-my-problem
• use a compressed image type like PNG or JPG to save the screenshot

If the problem continues in Firefox's Safe Mode, maybe:

The "bookmarks toolbar items" can be moved from the Bookmarks Toolbar to another bar by dragging them while the Customize feature is active. If you think that might have happened, you should be able to move them back to the Bookmarks Toolbar in a similar manner. This article should get you started:

Customize Firefox controls, buttons and toolbars

If needed, there's a button at the bottom of that panel to "Restore Defaults" which would move all the toolbar controls back to their starting positions.

OK, I think I've got it. Followed your suggestions. Problem doesn't occur in FF Safe Mode. Exited Safe Mode. Then disabled extensions one at a time. Problem disappears when "Tabs on Bottom" extension is disabled.

I've used this extension for a long time so it's most likely a conflict with the latest FF versions, 53, 52 & maybe 51. Hope the do an update to fix this.

Thanks for your support!

Yes, the reviews mention some issues, but not specific to the Bookmarks Toolbar:

https://addons.mozilla.org/firefox/addon/tabs-on-bottom/reviews/

In the past cor-el posted a custom style rule that could move the Tabs bar to the bottom. See, for example:

I want my tabs on bottom again, how do I do it? (January 2016)

I don't know whether that needs to be updated for Firefox 51+.

Thought I'd try the above suggestion to modify the userChrome.css file to put my tabs at the bottom. However, I can't seem to find that file!

Using Run, %APPDATA%\Mozilla\, then opening Firefox/Profiles/1zvyavlt.default, I find no Chrome folder and no .css files. Also a Windows, Start search finds no file by this name.

Does FF 53 still have a userChrome.css file? If so, where would I find it?

You need to create the chrome folder (lowercase) in the <xxxxxxxx>.default profile folder if this folder doesn't exist

• use a plain text editor like Notepad to create a (new) userChrome.css file in the chrome folder (file name is case sensitive)
• paste the code in the userChrome.css file in the editor window
• make sure that the userChrome.css file starts with the default @namespace line
• make sure that you select "All files" and not "Text files" when you save the file via "Save file as" in the text editor as userChrome.css.
  otherwise Windows may add a hidden .txt file extension and you end up with a not working userChrome.css.txt file

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 Directory:
  Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder
• http://kb.mozillazine.org/Profile_folder_-_Firefox

Followed the above instructions and now my Bookmarks Toolbar is where it belongs!

Thanks to all who contributed to teaching an old dog a new trick!

I am livid! Why should I have to go to these extraordinary lengths just to achieve this! Why can't Mozilla just give me that option? I HATE it that you disabled my Classic Theme Restorer and Tabs on Bottom add-ins. Were you trying to make things harder for people or what?

Hi klgrube, this thread is not about moving the Tabs bar. But since you posted here...

I don't speak for Mozilla, but I remember that tabs moved to the top in Firefox 4.0, which was released on March 22, 2011. You've had six and a half years to get used to it. But wait, you still don't have to get used to it because you can reverse it using a custom style rule.

Yes, using a style rule workaround does take a few extra steps compared with installing an extension. After you're worn out being angry, you can roll up your sleeves and:

Overview:

1. Open your currently active profile folder
2. Create a new folder named chrome
3. Create a desktop shortcut to the chrome folder for easier future access
4. Make sure Windows is set to show you file extensions like .txt and .css
5. Create a new text file inside the chrome folder named userChrome.css
6. Open userChrome.css and paste in your rules

Open your currently active profile folder

The quickest way to open the profile folder Firefox is using right now is to launch it from the Troubleshooting Information page. To access that page, you can use any of these methods:

• Click the menu button (what I call the “3-bar” menu button), then the “?” button, then Troubleshooting Information
• On the top menu bar, click Help, then Troubleshooting Information. To activate a hidden menu bar on Windows, tap the Alt key or the F10 function key.
• Type or paste about:support in the address bar and press Enter/Return to load it.

In the first table on the page, find the Profile Folder row and click the button to the right, which will say “Open Folder”, “Show in Finder” or “Open Directory” on Windows, Mac or Linux, respectively. This should launch a new window with your system's file browser (e.g., Windows Explorer).

Create a new folder named chrome

Normally, your profile does not contain a chrome folder unless you've been running Firefox for a very, very long time. To create a chrome folder, you can use the standard method provided by your file browser. For example, on Windows:

• Right-click a blank area of the list, click New, then Folder. Type chrome (all lower case) as the name of the new folder, then click away to complete the edit.
• Click the New Folder button. Type chrome (all lower case) as the name of the new folder, then click away to complete the edit.

Create a desktop shortcut to the chrome folder for easier future access

It is very likely that you will need to add or modify files to the chrome folder in the future. I recommend adding a shortcut to the folder on your desktop for easier access. To create a shortcut, you can use the standard method provided by your file browser. On Windows, right-click the chrome folder, click Send To, then click Desktop (as shortcut).

Make sure Windows is set to show you file extensions like .txt and .css

If you do not use Windows, you can skip this step.

Out of the box, Windows hides certain common file extensions to reduce the appearance of clutter. However, this makes it difficult to change a file extension when you want to. Since both .txt and .css are common file extensions, we need to (at least temporarily) turn off this feature.

In newer visions of Windows, where Windows Explorer has a “ribbon” at the top with a View tab, you can click View, then find the checkbox for “File name extensions” and check the box. In older versions of Windows, one of these methods should work:

• Activate the top menu bar by tapping the Alt key or F10 key, click Tools, then Folder Options, then the View tab. Uncheck the checkbox for “Hide extensions for known file types.”
• If Windows Explorer has an Organize button on the toolbar, click Organize, then Folder and Search options, then the View tab. Uncheck the checkbox for “Hide extensions for known file types.”

Create a new text file inside the chrome folder named userChrome.css

Double-click chrome to open the chrome folder. The method you use to create the userChrome.css file may vary depending on the features provided by your file browser. Here's how you can do it in Windows: Right-click a blank area of the list, click New, then Text Document. Type userChrome.css — with only the C capitalized — in place of Text Document.txt, then click away to finish the edit.

Add your rules

You can open userChrome.css in your favorite text editor (avoid anything that curves quotation marks or inserts formatting codes) and paste this as a starting point:

/* Tab bar below Navigation & Bookmarks Toolbars 
   For best results, show Title Bar or Menu Bar */
#nav-bar { /* main toolbar */
  -moz-box-ordinal-group: 1 !important;
  border-top-width: 0 !important; 
}
#PersonalToolbar { /* bookmarks toolbar */
  -moz-box-ordinal-group: 2 !important;
}
#TabsToolbar { /* tab bar */
  -moz-box-ordinal-group: 3 !important;
}

If that's not quite right, the maker of Classic Theme Restorer has some more sophisticated rule sets, including:

bookmarks_toolbar_multiple_lines.css

Classic Theme Restorer would be great, but it's now blocked by Mozilla as "legacy." Good grief. At least Mozilla could incorporate a modicum of the functionality of this add-in.

I sincerely find it unacceptable that I should have to create my own css file just to do this. This means that I have ti figure this out for each device I use, for each OS, etc. This should simply be an option I can choose.