You got here because of an issue with the Studio debugger. Here is some information that should help you identify a cause and find possible solutions.
The AptanaDebugger extension is available at https://github.com/aptana/studio3/blob/development/bundles/com.aptana.js.debug.core/res/firefox/aptanadebugger.xpi.
It is compatible with Firefox 3+ and Firebug 1.7+
- If, for some reason, your Debugger Plugin for Firefox did not work by default, download the above file.
- Then drag and drop that file on top of your Firefox.
- Complete installation and relaunch the debugger.