Soft state activation failed; session time-out of service '&1' is '&2'

What causes this issue?

You tried to activate the service for the soft state processing mode,
but then session time-out for your service is 00:00:00

System Response

The SAP Gateway framework has detected that the service has not been
enabled for working in the soft state processing mode.

How to fix this error?

Make sure that the session time-out for your service is greater than
00:00:00. You can adapt the session time-out in transaction
<DS:TRAN.SICF>SICF</>.
Check the note <ZH>https://service.sap.com/sap/support/notes/1986626
</>on detailed steps how to adapt the session time-out and<ZH> </>for
prerequisites and further information on the soft state processing mode.

Procedure for System Administrators

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.