Won't Sync to NAS After Update

[N9sg7]

FFS updated to 14.6 today, and now it won't sync any files to my NAS. It gives the following error for every file:
"Cannot write permissions of [file name]. ERROR_PRIVILEGE_NOT_HELD: A required privilege is not held by the client. [SetFileSecurity]"
I tried running as administrator, and the error is the same.

[xCSxXenon]

What happens if you revert to 14.5 by downloading it from this website?

[N9sg7]

I tried 13.9, since that was the newest version installer I had downloaded, and it worked fine. I installed 14.5 and got the same errors and failure. I hadn't upgraded in a while. My NASs are QNAP.