Unity Web Player 4.6.6f1 and lower (click-to-play), Windows has been blocked for your protection.

Why was it blocked?
Current versions of the Unity Web Player plugin have known vulnerabilities that can put users at risk.
Who is affected?
All Firefox users who have these versions of the plugin installed.
What does this mean?

The problematic add-on or plugin will be automatically disabled and no longer usable.

When Mozilla becomes aware of add-ons, plugins, or other third-party software that seriously compromises Firefox security, stability, or performance and meets certain criteria, the software may be blocked from general use. For more information, please read this support article.