I just got some updates today, which may have caused issues with the upper panel. I updated with
sudo apt update and
sudo apt upgrade, so maybe that caused some problem with the way updates are handled by the Elementary App Store? I don't know.
Anyways, what this means is that the panel remains the colour of the wallpaper, and whenever I try and click on "Apps", the date or any of the icons that show WiFi signal, Bluetooth, Battery or "Shut down", they do not do anything. It looks as if it has "frozen", and it does not work at all. Also, all of the menus are stuck, which means that the date, the battery level, etcetera, are stuck on the same way they were when it first froze.
I am not sure what is going on with it, so I post this in hopes that somebody can help me out.
Here is a screenshot of how it looks.