Comment 2 for bug 1905491

Thank you for taking the time to report this bug and helping to make Ubuntu better.

Bug reporting is mostly about finding & fixing problems thus preventing future users from hitting the same bug.

Ubuntu 20.10 was released in 2020-October (thus it's 20.10) and there have been no Ubuntu releases in November unless you include development/test releases (20.04.2, hirsute (21.04) etc)

There is no evidence of validate of ISO (esp. given the date stamp on the file you mention is wrong), etc. so I'd suggest it's a support issue.

I believe would be more appropriate, eg. https://answers.launchpad.net/ubuntu. You can also find help with your problem in the support forum of your local Ubuntu community http://loco.ubuntu.com/ or asking at https://askubuntu.com or https://ubuntuforums.org, or for more support options please look at https://discourse.ubuntu.com/t/community-support/709

I've accordingly marked this incomplete, if you believe I'm in error, or you've verified your ISO & believe it is an actual bug in the software/ISO, you can leave another message on this report and change the status back to "New". Please also provide specific details as to ISO, the sha256sums etc & details of how you verified they were valid.

FYI: Yes a number of changes were made during the groovy cycle in the way systems are booted, and they were gradually fixed as detected, eg. https://bugs.launchpad.net/bugs/1883040 https://bugs.launchpad.net/bugs/1886148 & others. You however haven't provided proof that normal validation of ISOs has been performed, checksums of ISOs matching what they should be etc.