The DNS server encountered invalid class token "%1" in zone file %2 at line %3. Although the DNS server continues to load, ...

The DNS server encountered invalid class token "%1" in zone file %2 at line %3.  Although the DNS server continues to load, ignoring this resource record (RR), it is recommended that you either correct the class of the RR to use the Internet (IN) class or remove the resource record from the zone file. The DNS server supports only the Internet (IN) class in RRs.