Rated 4 out of 5 stars

When loading Fx I see this warning in the error console:

Warning: Bootstrapped manifest not allowed to use 'overlay' directive.
Source File: jar:file:///C:/path/to/my/Firefox/profile/extensions/%7B421e87b4-d3d2-49c8-b08f-b83f4dc88444%7D.xpi!/chrome.manifest
Line: 3