What happened to my desktop?

Hello, Aletered-Ego!
Here is my sollution:

  1. Boot into Ubuntu.
  2. At the login screen, click the gear icon next to your username.
  3. Select “Budgie Desktop” from the list of desktop environments.
  4. Log in to your account.

If this does not work, you may need to reinstall the Budgie desktop environment. To do this, open a terminal window and run the following command:

sudo apt install budgie-desktop

Once the Budgie desktop environment is reinstalled, reboot your computer and you should be able to log in to the Budgie desktop environment by default.