2352098 - Configure CA Introscope - EM introscope is offline - http status code 403

During the Basic Configuration in transaction SOLMAN_SETUP, in step Configure CA Introscope, the system reports that it is offline with the following error being raised in the defaultTrace of the Solution Manager:

com.sap.smd.introscope.em.rest.EmRestGateway.test

Text Error accessing to Enterprise Manager: <host>@<port>
[EXCEPTION]
com.sap.smd.introscope.em.IntroscopeException: http status code 403
at com.sap.smd.introscope.em.rest.IntroscopeHttpConnection.executeQuery(IntroscopeHttpConnection.java:152)
at com.sap.smd.introscope.em.PooledConnection.executeQuery(PooledConnection.java:26)
at com.sap.smd.introscope.em.rest.EmRestGateway.performStatusQuery(EmRestGateway.java:80)
at com.sap.smd.introscope.em.rest.EmRestGateway.test(EmRestGateway.java:45)
at com.sap.sup.admin.wily.jdbc.EMInfo.test(EMInfo.java:387)
at com.sap.sup.admin.wily.jdbc.EMOverview.populateEmInfo(EMOverview.java:433)

• SAP Solution Manager 7.x.
• CA Introscope Enterprise Manager 9.x.

KBA , SV-SMG-DIA-WLY , Solution Manager / Introscope Integration , XX-PART-WILY , Introscope by CA Technologies , Problem