A fatal error has occurred and VcXsrv will now exit.

 

In the log, it’s the last lines in /tmp/win kexsl_user.log:

winMultiWindowXMsgProc - Fatal error 1 on xcb connection
winClipboardIOErrorHandler!
winClipboardProc - setjmp returned for IO Error Handler.
(II) Server terminated successfully (0). Closing log file.

here you can try to start Win-KeX with sudo:

sudo kex --sl --wtstart -s

A solution also brought the deletion of the logs under /tmp.

sudo rm -f /tmp/*.log

And stop the KeX server with the –stop and –kill option.

sudo kex --stop
sudo kex --kill

After that, the start of kex as a normal user became possible.

kex --sl --wtstart -s

Also, a Win-KeX reinstallation can fix the error:

sudo kex --stop
sudo kex --kill
sudo apt-get purge kali-win-kex
sudo apt-get install kali-win-kex
sudo apt-get install dbus-x11