No target host for background processing is currently active

What causes this issue?

You can specify a target computer when you schedule a job. This
specification determines which computer the corresponding job will be
executed on. The name entered is checked according to various
criteria.
There are several different causes for this message:
The check was attempted, but failed. No SAP system that supports
background processing could be found in the current configuration.
The system attempted to create an overview of all computers that
currently support background processing (e.g. have work processes of
the appropriate type). However, no such SAP system could be found.

System Response

This error message is output. In interactive mode, the name of the
target computer must be left blank. Please note that this field
can remain unspecified. If so, the load situation at execution time of
the job will determine the computer where the job is performed.

How to fix this error?

Check the current configuration of the active SAP systems. It is
possible that no background processing has been activated.
If this configuration is intended - that is, if background processing
should not be supported right now - then the function that triggered
this message cannot be performed right now (e.g. the display of
possible input values cannot be called).
Please also note that the name of the destination computer is not a
required entry. If it is not specified, the load situation at the
execution time of the job will determine the computer where the job
runs.

Error message extract from SAP system. Copyright SAP SE.