either restart the current machine / power off then power on the machine again to see if the problem has been killed

or if you can get access to a terminal via shortcut keys (CTRL+ALT+T) or right-click open terminal here etc then proceed to the process below

run this command: xfce4-panel

then close the terminal window by either going to "File> quit" or clicking the [ x ] in the top right corner. it's important that you close the current session and NOT kill the process via CTRL+C but only close the session window by the [ x ] or "File > Quit"

This report has been filed against an old version of Kali. We will be closing this ticket due to inactivity.
Please could you see if you are able to replicate this issue with the latest version of Kali Linux (https://www.kali.org/get-kali/)?
If you are still facing the same problem, feel free to re-open the ticket. If you choose to do this, could you provide more information to the issue you are facing, and also give information about your setup?
For more information, please read: https://kali.training/topic/filing-a-good-bug-report/