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 28fff16vf8dip7e83q5ell9fclfpupe3.comtecint.dk is not the root of its zone.
Instead, try zone transfer on comtecint.dk .
Instead, try zone transfer on comtecint.dk .