I upgraded my 20.04 installation to 21.04 last night via this command - sudo do-release-upgrade
It led to a prompt to upgrade which I agreed to. A couple of hours later the upgrade had completed but I found that most of the icons on LXQt were missing, including the quick shortcuts of the taskbar. They are ‘still there’ and clickable but invisible.
I am a real Lubuntu (and Linux) noob and wondered if there is anything relatively simple I can do to solve this.