Cant install packages

[creeperskinmaker]

discover wont work so i put sudo apt get update into Konsole and get

Hit:1 http://us.archive.ubuntu.com/ubuntu focal InRelease
Hit:2 http://us.archive.ubuntu.com/ubuntu focal-updates InRelease
Hit:3 http://us.archive.ubuntu.com/ubuntu focal-backports InRelease
Hit:4 http://security.ubuntu.com/ubuntu focal-security InRelease
appstreamcli: symbol lookup error: appstreamcli: undefined symbol: AS_APPSTREAM_METADATA_PATHS
Reading package lists... Done
E:  Problem executing scripts APT::Update::Post-Invoke-Success 'if  /usr/bin/test -w /var/cache/app-info -a -e /usr/bin/appstreamcli; then  appstreamcli refresh-cache > /dev/null; fi'
E: Sub-process returned an error code

pushed back so i try sudo apt get update -d and

Hit:1 http://us.archive.ubuntu.com/ubuntu focal InRelease
Hit:2 http://us.archive.ubuntu.com/ubuntu focal-updates InRelease
Hit:3 http://us.archive.ubuntu.com/ubuntu focal-backports InRelease
Hit:4 http://security.ubuntu.com/ubuntu focal-security InRelease
appstreamcli: symbol lookup error: appstreamcli: undefined symbol: AS_APPSTREAM_METADATA_PATHS
Reading package lists... Done
E:  Problem executing scripts APT::Update::Post-Invoke-Success 'if  /usr/bin/test -w /var/cache/app-info -a -e /usr/bin/appstreamcli; then  appstreamcli refresh-cache > /dev/null; fi'
E: Sub-process returned an error code

gets pushed back

also i can not open app images and it sends back
You might still be able to extract the contents of this AppImage
if you run it with the --appimage-extract option.
See https://github.com/AppImage/AppImageKit/wiki/FUSE
for more information
please help

[claydoh]

try clearing your package cache and see if it helps

sudo apt clean

then try again

sudo apt update

Note the different apt syntax for updating. It should not make a real difference, but may possibly show different error messaging using the more up-to-date command strings

[creeperskinmaker]

ok, it send back

hit:1 http://security.ubuntu.com/ubuntu focal-security InRelease
Hit:2 http://us.archive.ubuntu.com/ubuntu focal InRelease
Hit:3 http://us.archive.ubuntu.com/ubuntu focal-updates InRelease
Hit:4 http://us.archive.ubuntu.com/ubuntu focal-backports InRelease
appstreamcli: symbol lookup error: appstreamcli: undefined symbol: AS_APPSTREAM_METADATA_PATHS
Reading package lists... Done
E: Problem executing scripts APT::Update::Post-Invoke-Success 'if /usr/bin/test -w /var/cache/app-info -a -e /usr/bin/appstreamcli; then appstreamcli refresh-cache > /dev/null; fi'
E: Sub-process returned an error code

i was also using this guide to update to 20.04
https://help.ubuntu.com/community/FocalUpgrades/Kubuntu

and audio wont play anymore