Searched on Google with the first line of a JAVA stack trace?

We can recommend more relevant solutions and speed up debugging when you paste your entire stack trace with the exception message. Try a sample exception.

Recommended solutions based on your search

Solutions on the web

via GitHub by knockoutuser
, 2 years ago
This exception has no message.
via Stack Overflow by jasiuuu
, 1 year ago
java.lang.NullPointerException: 	at org.apache.tomcat.websocket.server.WsServerContainer.unregisterAuthenticatedSession(WsServerContainer.java:367)	at org.apache.tomcat.websocket.server.WsServerContainer.unregisterSession(WsServerContainer.java:344)	at org.apache.tomcat.websocket.WsSession.sendCloseMessage(WsSession.java:494)	at org.apache.tomcat.websocket.WsSession.doClose(WsSession.java:417)	at org.apache.tomcat.websocket.WsSession.close(WsSession.java:394)	at org.apache.tomcat.websocket.server.WsServerContainer.closeAuthenticatedSession(WsServerContainer.java:377)	at org.apache.tomcat.websocket.server.WsSessionListener.sessionDestroyed(WsSessionListener.java:40)	at org.apache.catalina.session.StandardSession.expire(StandardSession.java:808)	at org.apache.catalina.session.StandardSession.isValid(StandardSession.java:658)	at org.apache.catalina.session.ManagerBase.processExpires(ManagerBase.java:534)	at org.apache.catalina.session.ManagerBase.backgroundProcess(ManagerBase.java:519)	at org.apache.catalina.core.ContainerBase.backgroundProcess(ContainerBase.java:1352)	at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1530)	at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1540)	at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1540)	at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1519)	at java.lang.Thread.run(Unknown Source)