The problem started when I was trying to update a game on steam. The game couldn't be updated because it had a "disk write error" so I just rebooted the system, then steam wanted to update itself but after some time downloading the update it said there was a network problem and I clearly was connected to my WiFi, I even tried by cable and said the same thing, b.t.w. my router was working perfectly I tried on other devices and the Internet worked.
So I thought that maybe I needed to use sofware updater, and it was working well until some point where it says "An unhandlable error occurred. there seems to be a programming error in aptdaemon, the software that allows you to install/remove software and to perform other packagement related tasks".
I have also tried using "sudo apt-get update" but it says:
sudo: unable to open /var/lib/sudo/sebas411/0: No such file or directory Ignhttp://dl.google.com stable InRelease Ign http://dl.google.com stable Release.gpg Hit http://dl.google.com stable Release W: Not using locking for read only lock file /var/lib/apt/lists/lock E: Couldn't create temporary file to work with /var/lib/apt/lists/dl.google.com_linux_chrome_deb_dists_stable_Release - mkstemp (30: Read-only file system) W: Not using lockingfor read only lock file /var/lib/dpkg/lock E: dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem
I also can't open firefox and steam now says: "Fatal error: failed to save package manifest"
What can I do?