Your partman log shows that your /dev/sda has two partitions. This is not the disk configuration expected for a 20.04 system by default. Did you choose manual partitioning from the installer?
Were you given an error message on your screen? That message doesn't appear to be included in the bug report, can you paste it? Your logs also show a strange block device of /dev/mapper/ventoy, can you tell us what that is? ** Changed in: ubiquity (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1900361 Title: attempting to install 20.04 LTS on older PC To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/1900361/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs