I ran the below a few hours ago and everything was fine - now I am getting an integrity check error. Is there any on-going issue with the update servers?
>freebsd-update fetch
Looking up update.FreeBSD.org mirrors... 3 mirrors found.
Fetching metadata signature for 12.0-RELEASE from update4.freebsd.org... done.
Fetching metadata index... done.
The update metadata is correctly signed, but
failed an integrity check.
Cowardly refusing to proceed any further.
>freebsd-update fetch
Looking up update.FreeBSD.org mirrors... 3 mirrors found.
Fetching metadata signature for 12.0-RELEASE from update4.freebsd.org... done.
Fetching metadata index... done.
The update metadata is correctly signed, but
failed an integrity check.
Cowardly refusing to proceed any further.