When running an ASA Agent 12.8 for WebSphere, the Agent doesn't perform SSO as it seems to not handling the request and reports error at the initialization phase:
[7/26/22 17:23:45:984 CEST] 00000001 TrustAssociat E SECJ0384E: Trust Association Init Error. The Trust Association interceptor implementation com.netegrity.siteminder.websphere.auth.SmTrustAssociationInterceptor initialization failed. The error status/exception is java.lang.NullPointerException
at org.apache.logging.log4j.core.config.AppenderControl.<init>(AppenderControl.java:51)
at org.apache.logging.log4j.core.config.LoggerConfig.addAppender(LoggerConfig.java:200)
at com.netegrity.siteminder.agentcommon.utils.n.a(Unknown Source)
ASA Agent 12.8 on WebSphere ND 8.5.5.21 on RedHat 7;
Java 1.8.0_U321;
/opt/CA/asa/conf/AsaAgent-assertion.conf
Web Agent 12.52SP1CR0 on Front End IHS 8.5.5 on RedHat 7;
This is a known issue that requires Upgrade of the ASA Agent 12.8SP1 for WebSphere when it will be available , please reach out to Broadcom Support if additional details are required