Output requests can fail with message 'Frontend Unavailable' or 'Unable to connect to output processor' when an application tries to print from background to a Frontend printer, or prints from Update.
It is not possible to print via a frontend access method from a background job as there is no connection to the frontend when running in background mode. This is also mentioned in SAP Note
under "Restrictions" in section Solution.
Frontend printing from a batch process cannot work, as there is no GUI connection. Make sure the user's steps when printing do not take place via BTC (batch) processes.
If your SAP system is updated to at least the versions described in SAP Note
, then the status of the affected spool(s) will be " - " instead. This means that the printout will be automatically canceled on Kernel level, because (immediate) printing from a Batch Job to the Frontend - due to the above mentioned reasons - does not make sense.