The suggested v1.47 package worked! I did:
wget https://launchpad.net/ubuntu/+source/shim-signed/1.47/+build/21482148/+files/shim-signed_1.47+15.4-0ubuntu2_amd64.deb sudo dpkg -i ./sudo dpkg -i ./shim-signed_1.47+15.4-0ubuntu2_amd64.deb ... followed by a reboot, worked! (Booted OK with secure boot enabled). So I tried 1.48 again... sudo apt install shim-signed=1.48+15.4-0ubuntu5 ... followed by a reboot, did not work (Same as original report)
The suggested v1.47 package worked! I did:
wget https:/ /launchpad. net/ubuntu/ +source/ shim-signed/ 1.47/+build/ 21482148/ +files/ shim-signed_ 1.47+15. 4-0ubuntu2_ amd64.deb signed_ 1.47+15. 4-0ubuntu2_ amd64.deb 1.48+15. 4-0ubuntu5
sudo dpkg -i ./sudo dpkg -i ./shim-
... followed by a reboot, worked! (Booted OK with secure boot enabled). So I tried 1.48 again...
sudo apt install shim-signed=
... followed by a reboot, did not work (Same as original report)