Hi,

Please check if this happens in Safe Mode. Safe mode disables the installed Extensions, and themes (Appearance) in Tools (Alt + T) > Add-ons. Hardware acceleration is also temporarily disabled - the manual setting is Tools > Options > Advanced > General > Use hardware acceleration when available. All these settings/options/add-ons can also be individually or collectively disabled/enabled/changed in Firefox normal mode to check if an extension, theme, option or hardware acceleration is causing issues. Disabling/enabling hardware acceleration, and some types of add-ons in normal mode may require a Firefox restart.

Uninstalling Add-ons

Uninstalling Toolbars

Troubleshooting Extensions and Themes

Problematic Extensions

Options

If the problem persists you can also consider the Reset Firefox feature via Help (Alt + H) > Troubleshooting Information.

If you use the Customize feature, can you drag the new tab button back to the right end of the bar?

Alt+v (displays classic View menu) > Toolbars > Customize

Move the button palette out of the way so you can see the toolbars and adjust button positions.

If you don't mind losing changes you've made on your toolbars (e.g., moving icons around), you can reset them to their defaults, again using the Safe Mode dialog as noted above. This article illustrates the process: Changes to toolbars and window sizes are not saved.

Safe Mode did correct the problem; of course, that's not a viable solution (running without all my add-ons, toolbars, etc). I suppose I could experiment with disabling individual add-ons in the hope of finding which one(s) are causing the problem.

If things go as I expect, it will probably be an add-on that I can't live without, and the fact that I had not recently installed/upgraded any of my add-ons leading up to the problem makes me think that something (Firefox or something else) got corrupted.

Thanks for your suggestion, though.

jscher2000, I tried using the Customize feature, but I could not see any way to move items around. In fact, all I saw was a selection of icons that I could add to the Firefox Toolbar. I did not see anything about the new tabs (+) button or how to add/remove/move it.

This can also be a problem with the localstore.rdf file.

• http://kb.mozillazine.org/Corrupt_localstore.rdf

I tried using the Customize feature, but I could not see any way to move items around.

Just move that dialog aside. Look for the + on the tab bar (without the "tab" around it). Is it to the left of the tabs? If so, click and drag it to the right end of the bar.

I've seen this issue to, usually in a new (pop-up) window.
If I open a new tab in that window then that tab is appended to the right of the new tab button instead of to the left, so that button seems to be fixed to the left end of the tab bar and nothing shows to the left of it.
You should be able to use the Ctrl 1 to 8 shortcuts to reach the first 8 tabs.

This is a reply to all who provided suggestions: I was never able to figure out how to drag the 'New Tab' button from the left end of the Tab Bar to the right side. What I ended up doing was the following:

• Saved the tabs in both of my open windows as Bookmarks in the Bookmark Toolbar
• Changed the Startup options from 'Show my windows and tabs from last time' to 'Show a blank page'.
• Exited Firefox and restarted Firefox.
• Selected the list of saved Bookmarks for the first window and opened them all.
• Opened a new window and did the same thing regarding the saved bookmarks for that window.

Now both windows have the proper location for the New Tab button on the right side of the Tab Bar. Hopefully, this was some kind of one-time flukey behavior. I think I will also save a backup of my localstore.rdf file per the post by cor-el.

Thanks to all of you for your suggestions.