Do you think this might have something to do with copy protection? These are recorded using a cablecard through a TV Tuner. I don't typically record 30 minute long shows, but I always record in HD. The 30 minute shows are less than 6gb, but perhaps those channels have less copy protection? I don't understand why I can copy away to other machines, and across multiple platforms, but I cannot copy to FreeNAS. In fact, after upgrading to Windows 10, it kind of freaked out even worse. It gives the "You need to provide Administrator permissions" and when I clicked "Continue", it said that my "Y:\" drive was unavailable and just froze like that. I couldn't get rid of the screen error screen, but my Y: drive was still there and had no issues. Just in case it isn't apparent, my Y: drive is my main drive for the FreeNAS box. I went ahead and tried again, and I can still easily move these same files that are erroring over to other machines. I copied it over to my Mac over the network and it went fine.
If I could ditch the NextPVR backend, I would, but I like my live HD television. It only works in Windows though. :( Silicondust is building a full software DVR solution that runs on multiple platforms, including on certain NAS boxes. Does anyone know if FreeNAS is going to have an official plugin for Silicondust DVR from Silicondust?