The errors in your log show that the installer detected UEFI support at install time and tried to install the UEFI GRUB bootloader, which failed. There is no information in the log which explains why it failed at this point. The attached autogenerated information confirms that you were booted in BIOS mode when the report was filed.
You should remove the shim-signed and grub-efi-amd64-bin packages from your system. They are not installable on a system not booted in UEFI mode. ** Changed in: shim-signed (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1768695 Title: package shim-signed 1.34.9+13-0ubuntu2 failed to install/upgrade: installed shim-signed package post-installation script subprocess returned error exit status 1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/shim-signed/+bug/1768695/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs