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 420fd1c4f89fae40553e08d36b65df29.2db5c530a54d1dea2cf762737f941d18.comodoca.com is not the root of its zone.
Instead, try zone transfer on comodoca.com .
Instead, try zone transfer on comodoca.com .