@george1421 I ran a full chkdsk on that machine, and I still received the same error.
To see if the issue was isolated to that machine I grabbed another one, inventoried it, and ran a capture task without issue. I think we can safely call this issue solved at this point.
To all interested, Following the below guide solved my initial NFS issue with my QNAP:
https://forums.fogproject.org/topic/10973/add-a-nas-qnap-ts-231-as-a-storage-node-fog-v1-4
Thanks to everyone for their help with this project!