Just installed do not track 3.1.1030 above on Tor, it is enabled but when I click icon no window. Always shows '0'. Can it be fixed? Thanks.
Installing plugins and add-ons to Tor Browser is extremely discouraged.
The DNT add-on you mentioned would practically make your browser fingerprint unique since you'd be the only Tor user with a DNT header on. This may allow linkability of your actions on Tor.
Please consult to warnings on the downloads page:
Don't enable or install browser plugins
The Tor Browser will block browser plugins such as Flash, RealPlayer, Quicktime, and others: they can be manipulated into revealing your IP address. Similarly, we do not recommend installing additional addons or plugins into the Tor Browser, as these may bypass Tor or otherwise harm your anonymity and privacy. The lack of plugins means that Youtube videos are blocked by default, but Youtube does provide an experimental opt-in feature (enable it here) that works for some videos.