No SAP system is currently active on the specified computer

What causes this issue?

When a batch job is scheduled, you can specify a target computer. This
determines on which computer the job is executed. The name specified is
checked for the following:
At least one SAP system is running on the specified computer.
This SAP system is configured so that it can execute jobs, i.e. it
contains the work processes of the appropriate type.
A target computer was specified, on which an SAP system is not running.

System Response

The system displays this error message. You must correct the name of
the target computer. Please note that an entry in this field is not
mandatory. If no entry is made, the current system load will determine
which target computer is chosen for the execution of the job.

How to fix this error?

Correct the name of the target computer. If the name is correct, you
may need to start an SAP system there. Check that this system is
configured so that batch jobs can be executed.
Please also note that the name of the target computer is not a
mandatory entry. If no entry is made, the current system load will
determine which target computer is chosen for the execution of the job.

Error message extract from SAP system. Copyright SAP SE.