Nameščanje dodatkov za Firefox - napaka

Se opravičujem, če to že obstaja.
Poskusil sem z veliko dodatki za Firefox, pa mi nobenega noče namestit. Tudi pri poskusu posodabljanja obstoječih dodatkov se zgodi isto - napiše mi to:
"Firefox ne more prenesti datoteke xxx zaradi: Nepričakovana namestitvena napaka
Preglejte konzolo JavaScript za podrobnosti. -203"
V konzoli je pa to:
"Napaka: e.location.getItemLocation(e.id) is undefined
Izvorna datoteka: file:///C:/Program%20Files/Mozilla%20Firefox/components/nsExtensionManager.js
Vrstica: 4082" in v vrstici 4082 piše sledeče:
"var itemLocation = e.location.getItemLocation(e.id).QueryInterface(Ci.nsILocalFile);

Bi lahko bil za to kriv Nod3e2? Sem pred poskusom nameščanja dodatkov izklopil vso zaščito v Nodu, pa nima učinka.

A če bi shranil .xpi v računalnik in od tam povlekel v addon okno? Grem probat :)
Ne, isto, spet napiše, da je namestitvena napaka. A obstaja neka mapa za dodatke, v katero bi samo premaknil to .xpi stvar?
Je morda kriva Firefoxova verzija 3.0.14?

Unexpected installation error -203
This error message can be caused by either:
* corrupted configuration files on your computer. To resolve, see Corrupt extension files below.
* security software, which may be preventing these files from being updated

To je napisano na tej support strani, tako da je verjetno kriv nod32 oz. neka stvar v nastavitvah v nodu.
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Edit: rešil šem zadevo!
Problem ni v "security software, which may be preventing these files from being updated"
ampak v "corrupted configuration files on your computer. To resolve, see Corrupt extension files below."

Corrupt extension files

Corrupt extension configuration files can cause problems when trying to install an extension. Deleting these files will make Firefox recreate them (removing any corruption) the next time it starts. You won't lose your extensions or their settings by deleting these files.

1. From the menu at the top of the Firefox windowbar, select FileFirefox and then select the ExitQuit FirefoxQuit menu item.
2. Go to your profile folder.
3. Delete the following files:
* extensions.ini
* extensions.cache
* extensions.rdf
4. Restart Firefox.

Ko sem zbrisal te 3 datoteke, mi je brez težav inštaliralo dodatek.