Hi guys, I have made some changes via the sudo -R command because of the installation of dependencies for packages I needed for a robotics course, and after that I cannot execute the sudo command anymore and my internet connection is down. I am using Ubuntu 20.04. LTS. The other problem is that I cannot remember my root password to get access. I have posted a screenshot which describes the problem. Hope you can help me so I can proceed with my course. The chmod commands I issued in the screenshot are based on a google search to fix the problem but it doesn't work.