User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.6) Gecko/20070725 Firefox/2.0.0.6 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.6) Gecko/20070725 Firefox/2.0.0.6 I get the following error when I try to install the firebug plugin: Firefox could not install the file at https://addons.mozilla.org/en-US/firefox/downloads/file/15109/firebug-1.05-fx+fl.xpi because: Unexpected installation error Review the Error Console log for more details -203 Reproducible: Always Steps to Reproduce: 1. Go to Firebug page at addons.mozilla.org 2. Install Firebug 3. Actual Results: Firebug would not install. Expected Results: Firebug should have installed. The following error appears in the error console log after a failed install: Error: e.location.getItemLocation(e.id) has no properties Source File: file:///C:/Program%20Files/Mozilla%20Firefox/components/nsExtensionManager.js Line: 4141

This bug can be reproduced by attempting to install the Operator plugin as well.

Please update from Firefox/2.0.0.6 to 2.0.0.12 first.

Using 2.0.0.12, now. Problem persists.