1. Type about:config into the address bar and press Enter.
2. Press the big button to bypass the warning.
3. In the search box, paste extensions.readability.first_run_complete
4. In the search results, double-click extensions.readability.first_run_complete to set its value to true
5. Restart Firefox.
6. Right-click an empty area of the tab bar and choose Customize. Place Readability's icons wherever you like.

The problem you're describing is a bug in the add-on. I can confirm it, as do others who've posted reviews. Contact the authors of the add-on using either the "Support site" or "Support e-mail" links on the add-on's description page.

• https://addons.mozilla.org/firefox/addon/readability/

The readability-1.9-fx.xpi/defaults/preferences/defaults.js file shows two instances of the currentversion pref, so that is likely the cause of this issue and you can try to remove one of them or both to see if that helps (not tested by me).

pref("extensions.readability.currentversion","0");
pref("extensions.readability.currentversion","0");

XPI files are ZIP archives and best is to use an archive manager that can edit files directly from within the archive (most can do this).

Thank you for the fix that worked for Readability; however, there are other add-ons whose buttons seem permanently bound to the status bar, i.e., Right Links, No Squint, Search Tab, Fireshot, Translator, etc. The Organize Status Bar add-on only allows you to change the sequence of add-on buttons or hide (not remove) their appearance on the status bar. I have not found a way, consistent or otherwise, to tailor an add-on button's preference so I can move the button to a location of my choosing, not one that is assigned. I generally get either of 2 results whenever I try to move an add-on's button assigned to the status bar to another location: 1) the button remains attached to the status bar and the entire status bar moves as a complete unit, including buttons for other add-ons that have assigned buttons to a status bar location or 2) the button acts as if it can be moved away from the status bar, but as soon as you release the button in its new position, the button immediately jumps back to its previous status bar location. I had hoped there would be an easily-identifiable universal preference in every add-on to modify button location in about:config as appropriate. Are there any other options, you can recommend for a noob like me? Thank you again for your help.

Simply put, those add-ons really need to be updated.

The status bar was deprecated in Firefox 4. That means that since at least March 22nd, 2011, it was publicly known that the status bar shouldn't be used because it'll be removed at some point in the future.

That point came on April 29, 2014 with the release of Firefox 29. Although this release also removed the add-on bar, icons that were compatible with the add-on bar can be freely moved and placed on other toolbars or in the ≡ Menu Button panel.

With that bit of history out of the way, that means

1. The status bar / add-on bar you have right now is a replacement provided by another add-on, like Classic Theme Restorer, Status-4-Evar, The Addon Bar or The Puzzle Piece. Therefore there's no about:config preference or other built-in method to control status bar icons, because as far as Firefox is concerned, that's a defunct user interface element that no longer exists.

2. If you have Classic Theme Restorer, you can open its options window in the Add-on Manager, Extensions category and make sure "Movable status-bar" panel is checked. When in customize mode, you can then move the whole status bar shim to another toolbar (that's the entire cluster of icons like the NoSquint zoom level).

3. Organize Status Bar hasn't been updated in a very long time. if it still works, you can use it to rearrange the icons within the status bar shim, or hide them.

4. Look through the options window of each add-on in the Add-ons Manager, Extensions category. Some allow you to hide their icon on the status bar.

G-Man, thank you for your extraordinary insight. You're right, I'm using the Classic Theme Restorer add-on which I believe may be responsible for holding certain toolbar buttons hostage on the status bar.Unfortunately, when I disable the Classic Theme Restorer, it removes not only the status bar, but all of the separator, space, and flexible space toolbar buttons I use on all of my toolbars with it. :-( These toolbar buttons are invaluable. Having locked status bar buttons is the lesser of two evils to me. I wish there were some way for the Classic Theme Restore to include in its generous list of options the relocation of any status bar button to a user-specified location. Hiding a particular status bar button is not enough. (I can't get into the Support Forum to leave this request.) Thank you again.

foxxfirr wrote:

You're right, I'm using the Classic Theme Restorer add-on which I believe may be responsible for holding certain toolbar buttons hostage on the status bar.

No, the point I was trying to get across is that Firefox never offered any way to customize the status bar — back when it still had one built-in. Icons were always locked in place, and could only be hidden via the options window of the respective add-on, or rearranged within the status bar element using the Organize Status Bar add-on. Rest assured, Classic Theme Restorer is providing you with more features, not fewer.

foxxfirr wrote:

I wish there were some way for the Classic Theme Restore to include in its generous list of options the relocation of any status bar button to a user-specified location.

You can contact the author to request any features. Note that MozillaZine is an independent third-party site. You'll have to sign up for an account there, if you don't already have one.

• http://forums.mozillazine.org/viewtopic.php?f=48&t=2827985

Gingerbreads solution worked for me. Thank you