Good to hear that it's working for you now.
I installed Firebug 2.0.4 from
getfirebug.com (i.e. from
https://getfirebug.com/releases/firebug/2.0/) on a fresh Firefox 32.0 profile right now and didn't see any message like this.
If you encounter this problem again at some point, please post a screenshot of what you see and the precise steps you did, so we can investigate that. Thanks.
Sebastian