sed failure when creating iso for arm64

[step21]

Hey,

I am interested in an ISO for arm64 (mainly for vms on arm hardware).
The process works more or less after adjusting the configuration to use 22.04 (running from 22.04), but close to the end, there is a failure with sed claiming "no such file ../../../../data/Release". When I checked this manually, the file is there and the path seems to be correct too. So any idea why this would happen? Ideally, a path that is not relative might be better.