I got the same error. Therefore I first ran the container with a volume
/opt/unbound/etc/unbound2
then I copied everything from
/opt/unbound/etc/unbound
to
/opt/unbound/etc/unbound2
then I rebuild the container with the correct volumepath
/opt/unbound/etc/unbound
then you will see every file and the error is gone, though still some warnings are shown.
But: I cannot reach the Container from my Adguard container. Any ideas?
the Adguard runs on an own ip on unraid and unbound runs in bridged mode with port 5335 published.