No the addon devs will have to fix that bug. You can though try to troubleshoot the localstore.rdf file.

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

Hope they fix it. Thank you ^_^

A lot of Firefox's user interface can be modified using style rules, including hiding icons. If you find it really, really annoying, it might be worth investigating that. However, if you need the button sometimes, then hiding it might not be that useful.

I literally never use the icon, how can I do it ?

The DOM Inspector (DOMi) has a menu item (Edit > Select Element By Click) and a toolbar button "Find a node to inspect by clicking on it" (left icon on the toolbar in the DOMi).

• open the browser window in the DOMi (File > Inspect Chrome Document) and choose the first from the list.
• click the "Find a node to inspect by clicking on it" button and use the keyboard (Alt Tab) or the Task bar to go back to the browser window (do not click in the browser window other than the title bar).
• click that element with the mouse and keep the button pressed until you see a red border to indicate the the DOMi has located that element in the DOM tree.

That should bring you to this toolbar button and give you its ID.

• https://developer.mozilla.org/en/DOM_Inspector/Introduction_to_DOM_Inspector
• DOM Inspector: https://addons.mozilla.org/firefox/addon/dom-inspector-6622/

When I installed that addon.... No icon showed......

I can't install it for some reason, so I can't extract the ID from the toolbar. My best guess about the ID based on the extension's contents is:

#jid1-4P0kohSJxU1qGg@jetpack-toggle-button

If you have the Stylish extension, you could try the following new rule (create a new blank rule):

@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);
#jid1-4P0kohSJxU1qGg@jetpack-toggle-button {
  display:none !important;
}

Sorry I can't test this.