For this and similar error messages, check the following requirements:

1. Permissions for /usr/bin/callin and /usr/bin/callout must be rwsr-xr-x (4755).
2. Permissions on the full structure of the /usr/spool/uucp directory must be at least rw-rw-rw- (666). The lock file for the device will be placed in this directory.
3. Permissions on the port itself must be rw-rw-rw- (666).

UNIX Resets Port Permissions

This is for specific locked device issues on TERM for UNIX. The port itself gets reset to 600 after being changed to 666. The script included below solves the problem of callin/callout not being able to enable and disable ports that use port monitors. Place the script in /usr/bin and run chmod 0777 to make it executable and accessible to all from anywhere. It is very simple: it disables the port, makes it accessible to TERM, starts TERM, then re-enables the port.

/usr/sbin/pmadm -d -pttymon0 -s00
sleep 5
`chmod 0666 /dev/term/00
term
/usr/sbin/pmadm -e -pttymon0 -s00

This script is from Unisys U6000 SVR4 UNIX. This is an example script and not for all UNIX systems.