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 96c6dq05sp7vq8m311ufpu2485mkuk1h.builder.nu is not the root of its zone.
Instead, try zone transfer on builder.nu .
Instead, try zone transfer on builder.nu .