I got this sign this morning. Can’t type anything on browser. Can’t right click on pictures folder but can do right click on the desktop.
Also getting this during login in, the "@^ sign" was not showing before, this started since when the "not allowed sign" started. Link – https://imgur.com/gallery/jKWJSRE
Please help me in correcting this. New user (1 month).
[SOLVED] I went to settings, then "Keyboard Shortcuts", then under "Sound & Media", I saw "Play (or play/pause)" which was disabled. I enabled it by inputting a key for it, I chose the "play" button on my keyboard. After enabling the play button, I pressed it on my keyboard, since then the "not allowed" sign was gone. I fixed my issue, my ubuntu version is 20.04. WELCOME.