Firefox, Chrome and Safari
Unlike IE, the errors will not show up but they will be recorded into their respective web consoles.
When the browser seems not to be responsive it is probably because some sort of error occurred.
Firefox and Chrome: press Ctrl+Shift+J
Firefox Error Console:
Chrome error console:
Safari: press Ctrl+Alt+C
Whichever browser you are using the information above will be very useful for technical support purposes.