After 10.1 upgrade from the ssgconfig menu the status shows STARTING this could also occur when upgrading to GW 10.0 CR5 and above.
Process controller SSL errors on 2124 after upgrade
2022-03-24T12:49:35.009-0400 WARNING 1 com.l7tech.server.processcontroller.o: default may still be starting, but API is throwing unexpected exceptions
javax.xml.ws.WebServiceException: Could not send Message.
at org.apache.cxf.jaxws.JaxWsClientProxy.mapException(JaxWsClientProxy.java:183)
at org.apache.cxf.jaxws.JaxWsClientProxy.invoke(JaxWsClientProxy.java:145)
at com.sun.proxy.$Proxy97.ping(Unknown Source)
at com.l7tech.server.processcontroller.o.b(Unknown Source)
at com.l7tech.server.processcontroller.o.a(Unknown Source)
at com.l7tech.server.processcontroller.ProcessController.a(Unknown Source)
at com.l7tech.server.processcontroller.ProcessController.a(Unknown Source)
at com.l7tech.server.processcontroller.ProcessControllerDaemon.a(Unknown Source)
at com.l7tech.server.processcontroller.ProcessControllerDaemon.main(Unknown Source)
Caused by: javax.net.ssl.SSLHandshakeException: SSLHandshakeException invoking https://localhost:2124/ssg/services/processControllerNodeApi: Remote host terminated the handshake
Release : 10.0
Component : API GATEWAY
Customer only had TLS 1.0 enabled for listening port 2124, updated gateway disables TLS 1.0.
Policy Manager -> Tasks -> Transports -> Manage Listen Ports
Click “Node HTTPS (2124)” entry then click properties
Click SSL/TLS Settings
From Enabled TLS Version check TLS 1.1 TLS 1.2 TLS 1.3