Hi @gubu
Welcome to the IPFire Community.
Have a look at this thread and its links where other people have also been working at trying to get IPFire working on the Espressobin. They also had a similar message as you and found other ways to get it to boot. Might be of help to you.
https://community.ipfire.org/t/improving-aarch64-image-booting-espressobin-network-setup/4190