Troubleshooting: "javax.net.ssl.SSLException: Received fatal alert: certificate_unknown"

Use this topic to troubleshoot authentication errors in your WebSphere Application Server V8.5.5 Liberty logs.

Problem

You see the following error message logged in your WebSphere Application Server V8.5.5 Liberty log:
[ERROR ] CWWKO0801E: Unable to initialize SSL connection. Unauthorized access was denied or security settings have expired. Exception is javax.net.ssl.SSLException: Received fatal alert: certificate_unknown
at com.ibm.jsse2.j.a(j.java:35)
at com.ibm.jsse2.ap.a(ap.java:133)
at com.ibm.jsse2.ap.a(ap.java:250)
at com.ibm.jsse2.ap.j(ap.java:86)
at com.ibm.jsse2.ap.b(ap.java:437)
at com.ibm.jsse2.ap.a(ap.java:532)
at com.ibm.jsse2.ap.unwrap(ap.java:572)
at javax.net.ssl.SSLEngine.unwrap(SSLEngine.java:11)
at com.ibm.ws.channel.ssl.internal.SSLUtils.handleHandshake(SSLUtils.java:904)
at [internal classes]

Solution

This error can be safely ignored.

A report has been filed with the WebSphere Application Server team. Upgrading to a future version of WebSphere Application Server V8.5.5 Liberty may resolve this issue.