Minicom error solution “Device /dev/ttyS0 is locked”

Sometimes if the connection to Linux from which the connection was made via Minicom is lost, then the next time you start Minicom, you could see an error:

Device /dev/ttyS0 is locked.

The name /dev/ttyS0 may be different, depending on what COM port you have.
To avoid such an error, it is necessary to correctly shut down Minicom using the CTRL-A keys and then the Q key.

You can solve the problem by killing the process as a root user with the command:

killall -9 minicom

In Ubuntu, use the command:

sudo killall -9 minicom

Or you can simply delete the file «LCK..ttyS0» in the /var/lock/ directory.

After that, the error will not be displayed.