Gateway Version: Any/All.
The observed issue was using the SSG Menu to validate if the Gateway service was running the menu showed the gateway stuck in starting.
For example
# netstat -an | grep 8443
Showed listening.
In the original logs it could be seen that the SSG service was up, and the listen ports were listening for the gateway.
In the SSPC_0_0.log Error Stack,
Caused by: javax.net.ssl.SSLHandshakeException: DH ServerKeyExchange does not comply to algorithm constraints
at java.base/sun.security.ssl.Alert.createSSLException(Alert.java:131)
at java.base/sun.security.ssl.Alert.createSSLException(Alert.java:117)
at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:340)
at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:296)
at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:287)
at java.base/sun.security.ssl.DHServerKeyExchange$DHServerKeyExchangeConsumer.consume(DHServerKeyExchange.java:538)
If you log into policy manager.
Go into Tasks -> Transports -> Manage Listen Ports -> 2124 -> Properties
Check off Enable Default Ciphers list AND TLS 1.3.
Having all default ciphers enabled at the listen port and all TLS Versions.