If you see question marks in the XFCE4 Panel and you don’t need to use the option to change the keyboard and layout, you can easily solve this problem.
This problem is caused by a package called fbxkb:
Right-click these question marks in the XFCE4 panel and select the Quit option:
Next, open a Terminal and run a command that will remove this package from the installation:
sudo apt remove fbxkb
This removal process is fast and takes about as long as this printout in Terminal that describes the process of removing this package:
$ sudo apt remove fbxkb Reading package lists... Done Building dependency tree... Done Reading state information... Done The following packages will be REMOVED: fbxkb 0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded. After this operation, 139 kB disk space will be freed. Do you want to continue? [Y/n] y (Reading database ... 327371 files and directories currently installed.) Removing fbxkb (0.6-3) ... Processing triggers for menu (2.1.48) ... Processing triggers for man-db (2.9.4-2) ...
The next time you restart the operating system, the question marks in the XFCE4 Panel will no longer appear.
In case you need this package sometime in the future, you can easily install it with the command:
sudo apt install fbxkb