Read only file system after update failure

Question

I tried to install some updates on my Ubuntu 20.04. If failed with the below error:

There seems to be a programming error in aptdaemon, the software that allows you to install/remove software and to perform other package management related tasks.

Then I tried to continue with a partial update. But my password have been changed or corrupted. I can't run anything with sudo either because this password issue. Most of the settings cannot be changed in the settings app. File system seems to be read only. No external drives are mountable.

How can I resolve this error?

Answer 1

There was a file corruption on root partition. Had to run fsck manually upon reboot.

Also there were duplicates on the apt config. Had to remove them manually too. How can I fix apt error "W: Target Packages ... is configured multiple times"?