You can accept the warning and click I'll be careful to continue. * = true You can open the about:config page via the location/address bar. You can try to set this pref to true on the about:config page.
Fx_cast is an extension for Firefox that addsCasting abilities to Mozilla Firefox browser. In the URL bar, type about:config and press Enter Home Chromecast extension Firefox How to Use Chromecast on Firefox to Cast Movies to Your T
