Spark doesn't start

Spark doesn’t startup anymore. I get the following stacktrace in error.log:

java.lang.reflect.InvocationTargetException

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.lang.reflect.Method.invoke(Unknown Source)

at org.jivesoftware.launcher.Startup.start(Startup.java:83)

at org.jivesoftware.launcher.Startup.main(Startup.java:33)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.lang.reflect.Method.invoke(Unknown Source)

at com.exe4j.runtime.LauncherEngine.launch(Unknown Source)

at com.exe4j.runtime.WinLauncher.main(Unknown Source)

Caused by: java.lang.IndexOutOfBoundsException: Index: 0, Size: 0

at java.util.ArrayList.RangeCheck(Unknown Source)

at java.util.ArrayList.get(Unknown Source)

at org.jivesoftware.LoginDialog.getDnsKdc(LoginDialog.java:1179)

at org.jivesoftware.LoginDialog.access$1100(LoginDialog.java:97)

at org.jivesoftware.LoginDialog$LoginPanel.useSSO(LoginDialog.java:708)

at org.jivesoftware.LoginDialog$LoginPanel.(LoginDialog.java:390)

at org.jivesoftware.LoginDialog.invoke(LoginDialog.java:133)

at org.jivesoftware.Spark.startup(Spark.java:165)

… 12 more

Does anyone know what the problem might be?