When i try to see any media that requires plugin-container to boot, it boots up and then immidiately closes, and boots up again and so forth until it just gives up. It doesn't affect anything else in the browser other then inability to use any flash applications, such as youtube videos, other types of video-services and flash-based games. The plugin-container for Unity applications works fine and is not affected. I tried to reinstall Firefox and reset it, but it didn't work.