query: Having trouble upgrading from 18.04 to 20.04 likely due to lack of valid signature on older unsupported versions
positive_passages.docid: 120
positive_passages.text: How do I restore the default repositories?
negative_passages.docid: 60659
negative_passages.text: Install newer package version from trusty-backports
negative_passages.docid: 129101
negative_passages.text: Upgrading Ubuntu 9.04 to 9.10 when Update Manager doesn't let you
negative_passages.docid: 15687
negative_passages.text: How do I resume a release upgrade?
negative_passages.docid: 126659
negative_passages.text: upgrade from 11.10 to 12.04 - No upgrade option available in update manager
negative_passages.docid: 12578
negative_passages.text: How do I upgrade to a newer version of Ubuntu?
negative_passages.docid: 128471
negative_passages.text: How do I update from 9.0.10 to 9.1.0?
negative_passages.docid: 119920
negative_passages.text: Failed upgrade from Ubuntu 19.10 to 20.04 "Please update the microcode"
negative_passages.docid: 28247
negative_passages.text: Google Chrome PPA upgrade invalid signature
negative_passages.docid: 80899
negative_passages.text: "no public key available" on apt-get update
negative_passages.docid: 48809
negative_passages.text: "The upgrade has aborted" error, how to proceed?
negative_passages.docid: 86777
negative_passages.text: Distribution upgrade problem "No new release found"
negative_passages.docid: 6833
negative_passages.text: Why is my Ubuntu 18.04 distribution asking me to upgrade to Pop!_OS 19.10?
negative_passages.docid: 23096
negative_passages.text: How to remove obsolete packages after failed release upgrade via do-release-upgrade on Ubuntu?
negative_passages.docid: 8526
negative_passages.text: Upgrading from Ubuntu 16.04 to 18.04 broke the system completely!
negative_passages.docid: 130374
negative_passages.text: Error saying "unable to update ICE authority" while booting
negative_passages.docid: 4660
negative_passages.text: Should I be offered the option to upgrade to 18.04.1?