If FreeBSD’s pkg refuses to update because of a wrong OS version, for example because you are in a FreeNAS jail and version mismatch are bound to happen, then you can always try to force the OS version in pkg (which you can find with uname -UK. Either put OSVERSION={{version}} in /usr/local/etc/pkg.conf or start it with pkg -o OSVERSION={{version}} where {{version}} is the target version, for example 1101001.