Changes since SOA version
IXFR is a zone transfer request that returns changes since a specific SOA version. Enter the SOA version to request changes since then.
Not an apex domain
The domain 8c9mrn955unf1q0rfgaqk75u2n4v5msp.vjm.dk is not the root of its zone.
Instead, try zone transfer on vjm.dk .
Instead, try zone transfer on vjm.dk .