Client changed both SC and APM from non SSL to SSL (using self signed certificate) and now calls from SC to APM failed.
Somehow the URL to APM still carries the non SSL URL on port 99, instead of the SSL on port 443.
Release : 17.4
Besides changing the Service Catalog configuration (Administration-->Configuration-->CA APM Web Service)
the following query would need to run on the MDB
update ca_application_registration set product_specific_data='HTTPS://apm-server-name:443/ITAM' where product_name='CA Asset Portfolio Management'