Report /UI5/APP_INDEX_CALCULATE is not scheduled as background job

What causes this issue?

The report /UI5/APP_INDEX_CALCULATE is not scheduled as background job
in the system.
The regular execution of that report is necessary for the application
index being up to date.

System Response

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

How to fix this error?

Schedule report /UI5/APP_INDEX_CALCULATE in a background job.
For more information, see the
<DS:RE./UI5/APP_INDEX_CALCULATE>report documentation.</>

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.