hey @CadeHenschen there are very specific documentations and step-by-step guides for distribution upgrades:
See here: https://docs.cloudron.io/guides/upgrade-ubuntu-20/
Is this happening midway and has there already been some data restored at /home/yellowtent/boxdata/mail/... or is this the first file which fails there?
Also what are the permissions and owner for /home/yellowtent/boxdata/ ?