Bug:
Network streaming is gone with this update. I watched a file last night perfectly, updated this morning and now that same file cannot play (or rather does and is very stuttery with no sound).
Fixed:
After leaving the machine for a while it worked perfectly. I have 4tb of files on the local connections. I imagine the new firmware was updating the file index or something.
Try leave your machine on for ±3 hours and then try again.