DFS1258I SYMBOLIC NAME 3270-A`nn` IS INVALID

Explanation
The symbolic name 3270-Ann specified in the DEV= parameter is invalid.
The number nn appended to 3270-A was not within the range "1
to 15", or the length of nn was less than 1 or more than 2.

System action
The control statement will be ignored, and execution will continue with
the control statement following.

Programmer response
Correct the specification in the control statement, and resubmit the job.