softshutdown.sh Fails with "Device or Resource Busy"

[rej4449]

I've set up a new Octopi server on a Raspberry Pi 4b.  I'm trying to get scripts working before I connect the ATXRaspi.  I created the softshutdown.sh script in /usr/local/bin/ and set the correct permissions.  When I try to run sudo softshutdown.sh, I get an error:

/usr/local/bin/softshutdown.sh: line 5: echo: write error: Device or resource busy

When I check permissions on file "export", I see:

-rwxrwx---  1 root gpio 4096 Sep 24 14:39 export

I cannot figure out how to clear this error.  My Linux skills aren't up to the task.  Can you help?  Thanks.

[rej4449]

I should add that when I run "echo 10 > /sys/class/gpio/unexport" and then run atxshutdown.sh, the script completes but it does not shutdown or reboot the raspi.