Do you see an overflow chevron (>>) at the at the right end of the Bookmarks Toolbar when this happens?

Does this folder reappear when you make the Firefox window wider or full screen?

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

When I switched to the default theme, while the window is not maximized I do see the chevron, yet Firefox still maintains a spot where the folder would normally go. When i remaximize, the chevron is gone but the folder does not re-appear (the gap where it should be is still there though).

Interesting, in Safe Mode it is working fine! My only two plugins are LastPass and UBlock Origin though! Hardware acceleration is already disabled/unchecked.

Edit: Back in normal mode, I disabled LastPass, restarted FF, and the issue still occurred. I reenabled Lasspass, and disabled Ublock, restarted FF, but the issue still occurred. What other settings could Safe Mode be hitting?

Suggestion:

Try moving the Bookmarks button back to the right-side of the URL . Location bar. The Australis has some undesirable quirks, and that may be one,

the-edmeister-3 said

Suggestion: Try moving the Bookmarks button back to the right-side of the URL . Location bar. The Australis has some undesirable quirks, and that may be one,

Moved that button to the right, but no luck, my folder still is disappearing. Tried with several different themes.

Any idea of why it might not be disappearing in Safe Mode? Besides disabling my plugins (uBlock Origin and LastPass which were determined to not cause the issue), what else does Safe Mode effect?

Firefox's Safe Mode also disables any userChrome.css or userContent.css file you might have created to customize the interface (userChrome.css) or web sites (userContent.css). This files do not exist in a new installation, only if you (or an add-on) have created them.

Firefox's Safe Mode also disables "hardware acceleration" which causes Firefox to fall back to a slower but sometimes more reliable method of rendering text and graphics. This is a setting you can manage independently if you like.

Windows: "3-bar" menu button (or Tools menu) > Options Mac: "3-bar" menu button (or Firefox menu) > Preferences

In the left column, click Advanced. On the right side, with the "General" mini-tab active, uncheck the box for "Use hardware acceleration when available".

This takes effect the next time you exit Firefox and start it up again. Any difference?

Since hardware acceleration improves the appearance of fonts and animations, you may want to check whether graphics card/chipset driver updates are available for your system. This article suggests safe ways to do that: Upgrade your graphics drivers to use hardware acceleration and WebGL.

Hmm, I have no idea how to customize userChrome or userContent but I generally don't go crazy when installing plugins and right now only have Lastpass and uBlock installed. I also already had hardware acceleration unchecked FYI.

Thanks for the suggestions though!

Are you using the default theme?

Correct. I've verified other themes act similarly.

In Customize I've also tried moving "Bookmark Toolbar Items" (where the folder of bookmarks is) to the left of the URL bar. When I unmaximize, it breaks similarly to what's been described above. There is a placeholder where the folder should be as well as the chevron and if you click the chevron you see the folder. If I remaximize the chevron is gone but the placeholder where the folder should be is still there.

Interesting note. If I add the bookmarks toolbar to the browser (the row under the URL area) and put the folder there, it doesn't disappear when unmaximizing and remaximizing.

HeyThere1 said

Interesting note. If I add the bookmarks toolbar to the browser (the row under the URL area) and put the folder there, it doesn't disappear when unmaximizing and remaximizing.

You know, I just assumed that was what you were doing all along. Where was it disappearing from if not from the Bookmarks Toolbar toolbar?

The screenshot in the question shows that you were opening the "Show your bookmarks" drop-down list and had relocated this button to the far left (the star isn't visible though). If you would have the "Bookmarks Toolbar folder items" not on the Bookmarks Toolbar, but on another toolbar (Navigation Toolbar or Tab bar) then this can possibly cause issues because of conflicts with flex properties.

If you are using code in userChrome.css then this could possibly cause this issue.

• http://kb.mozillazine.org/userChrome.css

Sorry for the confusion. This link shows what I mean. When the folder is on the toolbar, and the toolbar is placed below the URL row, it doesn't disappear when resizing the window. The second image shows that when it is on the same row as the URL area, when resized it disappears (third picture). What's interesting is that if I resize after that third picture there is still that gap where the folder is supposed to display but I get a chevron that does expand out to show it. If I remaximize though, the chevron goes away and shows what that third picture shows (a gap where the folder should be).

http://imgur.com/a/4pWSB

I went to my user folder and I don't have a chrome folder or a userchrome.css when searching that whole directory.

Just wanted to say a quick thanks to everybody who has all helped so far. I appreciate the responses!

It sounds like there is something glitchy about how the "Bookmarks Toolbar Items" shrink to fit the available space. You don't notice it on the Bookmarks Toolbar because there is so much more space available.

One workaround might be to make sure there is enough space for your key bookmarks even when the window is resized, but the address bar is a space hog and it may be a little complicated to shrink it. One method is use Customize and add the search bar back to the bar immediately to the right of the address bar. When you exit Customize and hover your mouse over the gap between the address bar and search bar, a resizing arrow should appear. Then you can click and drag left to allocate less space to the address bar. Finally, right-click > Remove the search bar. If that doesn't help, some more drastic actions might be required.

No luck - when I right click and remove the Search Bar, the URL Bar quickly expands to fill the space the Search Bar was using.

Are you able to reproduce anything like this in your browser? Is it in fact a real bug?

Side note as a reminder, despite the non-default skin in that last picture album, this issue occurs with default skin as well.

As cor-el mentioned the flex properties for the Location Bar (aka URL Bar) and the Search Bar combined can go awry when one is moved to another Toolbar or put in the menu Panel (what appears when you click the 3-Bar button). IMO that flex has too much priority and it's been like that since Firefox 29 (Australis UI) came out and from what I have seen it's not a Bug, just a quirk that few people ever see. "We" are among the "lucky few" that have seen that "quirk".

I have seen a similar problem to yours when moving the Bookmarks Toolbar Items to the Navigation Toolbar (that's where the Location Bar and the Search Bar are located by default). A customization that I have done for years, until Firefox 29 came out and I started having problems with folders disappearing.

I got around that quirk by "killing" the flex properties by fixing the width of both the Location Bar and the Search Bar via userChrome.css. I see no other way if eliminating that quirk. http://kb.mozillazine.org/UserChrome.css

This is the code that I use.

#urlbar-container {max-width:1050px!important}
#search-container {max-width:200px!important}

Vary the 1050 & 200 numbers to fix the sizes for each that works to your liking.

Beyond that, the best that I can think of is to re-do all your customizations and reapply them in a different order to see if that works better for you. Or cut back on the changes via Customize and set a priority for what is most important to you.

Wish I could say that "things will get better", but on the contrary, things are liable to get worse.

HeyThere1 said

Are you able to reproduce anything like this in your browser? Is it in fact a real bug?

I have not tried that layout. I have a ton of stuff on my rarely used Bookmarks Toolbar so I'm sure it would be chaos trying to shoehorn it onto my Navigation Toolbar.

I think the-edmeister's suggestion to use a custom style rule is the most reliable way to control the situation. Sometimes clearing the stored width value can help. Here's how:

Open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, click the "Open Folder" button. This should launch a new window listing various files and folders in Windows Explorer.

Leaving that window open, switch back to Firefox and Exit, either:

• "3-bar" menu button > "power" button
• (menu bar) File > Exit

Pause while Firefox finishes its cleanup, then rename xulstore.json to something like xulstore.old. If you see a file named localstore.rdf, rename that one to localstore.old.

Start Firefox back up again, and it should recalculate the address bar width. It may also restore the search bar and hide the menu bar or bookmarks toolbar, but your other customizations should remain intact.

jscher2000 winner winner!!! Renamed xulstore and localstore, relaunched and it no longer disappears when resizing.

Thank you so much for your persistence on this one!