I'm having problems when Iḿ trying ¿to install any package or software. My OS is Ubuntu 20.04. I've already tried all the solutions mentioned in this post https://bugs.launchpad.net/ubuntu/+source/dpkg/+bug/1871963, including configure the UEFI, following the next comand lines:
# sudo apt-get purge grub\*
# sudo apt-get install grub-efi
# sudo apt-get autoremove
# sudo update-grub
etc.
The error message appears even when the upgrades and is installed an app from the "Ubuntu Software" application...
Errors were encountered while processing:
grub-efi-amd64-signed
E: Sub-process /usr/bin/dpkg returned an error code (1)
Thanks!
I had this same problem the last few days. Months ago I installed Ubuntu 20.04 alongside Win10 I had to switch the BIOS to AHCI from RAID as it wouldn't allow install. Then after install I could switch back to RAID to allow Win10 dual boot. However along some update it messed it up and I had to switch back to AHCI and reinstalled grub as above. It sorted the problem.