this is a copy of the error message i get.... Firefox could not install the file at https://addons.mozilla.org/firefox/downloads/latest/748/addon-748-latest.xpi?src=addondetail because: Unexpected installation error Review the Error Console log for more details. -203 and this is a copy from my error console Error: e.location.getItemLocation(e.id) is null Source File: file:///C:/Program%20Files%20(x86)/Mozilla%20Firefox/components/nsExtensionManager.js Line: 3533 Please tell me what i need to do to fix this!