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 vfk3lk16mvduv9l4t971l6otd9vclbem.comtecint.dk is not the root of its zone.
Instead, try zone transfer on comtecint.dk .
Instead, try zone transfer on comtecint.dk .