Comment 2 for bug 1770504

The upgrader does not support unknow version from third party (ppa packages are logged as broken).

Use 'ppa-purge' for each ppa, to downgrade to genuine ubuntu version, then check none of these ppas are active.
Next step is to clean the system via 'gtkorphan' & 'bleachbit' (as root, carefully select options)

After rebooting the dist-upgrade script should be happier.