Error scheduling transactional RFC call in the background

What causes this issue?

The system could not schedule a background job with delayed start. The
background processor returned an error.

How to fix this error?

Start the function module manually using Transaction SM58. You must
find out why the system could not schedule any background jobs.
One possible cause is that the date or time are in the past.

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.