When you entered the TSO/E OMVS command or OPEN subcommand, close to the maximum number of processes were already active for this UID. Because of this, the process required for the shell could not be created. At least two processes must be available for this UID when you run the TSO/E OMVS command. Also, at least one process must be available for this UID when you run the OPEN subcommand. Each shell session takes up at least one process for this UID. Active z/OS UNIX batch jobs submitted for this TSO/E user ID count as processes for this UID. Other TSO/E user IDs may share the same UID with this TSO/E user ID. If those user IDs are currently using z/OS UNIX, their processes also count toward the maximum allowed for this UID.
The shell session is not started. If there are no other active sessions, the OMVS command ends and returns to TSO/E.
If required, increase the maximum number of processes allowed for a UID. This number is specified in the parmlib member for z/OS UNIX. For information about configuring z/OS UNIX, see z/OS UNIX System Services Planning.
For an explanation of the errno and reason code from attach_exec, see z/OS UNIX System Services Programming: Assembler Callable Services Reference. Follow any suggested actions for this errno value and reason code.
Try not to start so many shell sessions. Specify fewer initial sessions on the TSO/E OMVS command.
Wait for any z/OS UNIX batch jobs from this TSO/E user ID to end before reentering the OMVS command or OPEN subcommand. Other TSO/E user IDs may share a common UID with this user ID. Reenter the OMVS command or OPEN subcommand after one of those TSO/E user IDs has finished using z/OS UNIX.
Ask the system programmer to increase the maximum number of processes allowed per UID.