This is an error that occurs when a mod_auth_kerb protected webapp is being accessed, and I have no idea what the cause might be. Can anyone give hints as into which direction I should look? Thankful for any help!

    Search Subject for Kerberos V5 ACCEPT cred (HTTP/[email protected], sun.security.jgss.krb5.Krb5AcceptCredential)
Found key for HTTP/[email protected](23)
Entered Krb5Context.acceptSecContext with state=STATE_NEW
>>> EType: sun.security.krb5.internal.crypto.ArcFourHmacEType
Checksum failed !
16:36:30,248 TP-Processor31 WARN [site.servlet.KerberosSessionSetupPrivilegedAction] Caught GSS Error
GSSException: Failure unspecified at GSS-API level (Mechanism level: Checksum failed)
at sun.security.jgss.krb5.Krb5Context.acceptSecContext(Krb5Context.java:741)
at sun.security.jgss.GSSContextImpl.acceptSecContext(GSSContextImpl.java:323)
at sun.security.jgss.GSSContextImpl.acceptSecContext(GSSContextImpl.java:267)
at sun.security.jgss.krb5.Krb5Context.acceptSecContext(Krb5Context.java:741)
at sun.security.jgss.GSSContextImpl.acceptSecContext(GSSContextImpl.java:323)
at sun.security.jgss.GSSContextImpl.acceptSecContext(GSSContextImpl.java:267)
at org.alfresco.web.site.servlet.KerberosSessionSetupPrivilegedAction.run(KerberosSessionSetupPrivilegedAction.java:95)
at org.alfresco.web.site.servlet.KerberosSessionSetupPrivilegedAction.run(KerberosSessionSetupPrivilegedAction.java:44)
at org.alfresco.web.site.servlet.KerberosSessionSetupPrivilegedAction.run(KerberosSessionSetupPrivilegedAction.java:44)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:337)
at org.alfresco.web.site.servlet.SSOAuthenticationFilter.doKerberosLogon(SSOAuthenticationFilter.java:994)
at org.alfresco.web.site.servlet.SSOAuthenticationFilter.doKerberosLogon(SSOAuthenticationFilter.java:994)
at org.alfresco.web.site.servlet.SSOAuthenticationFilter.doFilter(SSOAuthenticationFilter.java:438)
at org.alfresco.web.site.servlet.SSOAuthenticationFilter.doFilter(SSOAuthenticationFilter.java:438)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:555)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:190)
at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:291)
at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:774)
at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:703)
at org.apache.jk.common.ChannelSocket$SocketConnection.runIt(ChannelSocket.java:896)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:690)
at java.lang.Thread.run(Thread.java:662)
Caused by: KrbException: Checksum failed
at sun.security.krb5.internal.crypto.ArcFourHmacEType.decrypt(ArcFourHmacEType.java:85)
at sun.security.krb5.internal.crypto.ArcFourHmacEType.decrypt(ArcFourHmacEType.java:77)
at sun.security.krb5.EncryptedData.decrypt(EncryptedData.java:168)
at sun.security.krb5.KrbApReq.authenticate(KrbApReq.java:268)
at sun.security.krb5.KrbApReq.<init>(KrbApReq.java:134)
at sun.security.jgss.krb5.InitSecContextToken.<init>(InitSecContextToken.java:79)
at sun.security.jgss.krb5.Krb5Context.acceptSecContext(Krb5Context.java:724)
... 24 more
Caused by: java.security.GeneralSecurityException: Checksum failed
at sun.security.krb5.internal.crypto.dk.ArcFourCrypto.decrypt(ArcFourCrypto.java:388)
at sun.security.krb5.internal.crypto.ArcFourHmac.decrypt(ArcFourHmac.java:74)
at sun.security.krb5.internal.crypto.ArcFourHmacEType.decrypt(ArcFourHmacEType.java:83)
... 30 more