Application engine with ID &1 does not exist

What causes this issue?

In Customizing for the SAP Application Interface Framework under
<ls>Additional Interface Properties -></> <DS:SIMG./AIF/INF_ENG>Define
Interface Engines</>, an application engine was defined that does not
exists.

System Response

The system cannot handle messages of the interface.

How to fix this error?

Contact your system administrator or interface developer.

Procedure for System Administrators

Check which application engine is selected for the interface. Maintain
an existing application engine ID.

Error message extract from SAP system. Copyright SAP SE.