The SRU of 3.103 to focal (LP: #1904890) on 2021-01-28 (one day after @grudzinski-gmail's comment) should have fixed this. I'll set this to Fix Released for now as I'm *fairly* confident this is indeed fixed, but if you're still having this issue please do set it back to "New" and I'll dig into it.
** Changed in: flash-kernel (Ubuntu) Status: Confirmed => Fix Released -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1904024 Title: package flash-kernel 3.98ubuntu12 failed to install/upgrade: installed flash-kernel package post-installation script subprocess returned error exit status 1 when installing on a Raspberry Pi 400 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/flash-kernel/+bug/1904024/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs