Midnight Commander freezes host when invoked from panel launcher

[Rich Shepard]

System: Lenovo ThinkPad T430 running Slackware64-15.0.

Midnight Commander (mc) is a dual-pane, text-mode file manager. When I
invoke it in a virtual terminal it loads and displays as it does on my other
network hosts. But, when I added it to a panel 2 launcher the same command,
`/usr/bin/mc' locks the system. It does not display the application and
neither mouse clicks or keyboard commands (other than ctrl-alt-F[n] which
changes to a text console from the GUI. A system reboot is required to
recover.

What might cause this freeze?

Regards,

Rich