Updating to 4.6b1 on unraid - Transcoding video issues

[Swixxy]

I have recently just upgraded my subsonic on my unraid box to 4.6b1 and since the upgrade my videos fail to transcode, it was working fine beforehand - However i noticed that the transcoding string is different?

(Error comes up with Video not found or access denied)

Is anybody running 4.6b1 on unraid that could give me some pointers?

Thanks a bunch!

Edit: just had another quick glance at the error log and i noticed that it seems to be saying that the -preset argument isn't valid? So possibly an out dated ffmpeg?