xe-3-0-0.cr1.th-lon.zen.net.uk IXFR zone transfer

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 xe-3-0-0.cr1.th-lon.zen.net.uk is not the root of its zone.
Instead, try zone transfer on zen.net.uk .