Upgraded from Hudson 1.300 to 1.303 (master on Solaris 10 x86 Java 1.6.0_10).

Prior to upgrade was able to configure a matrix project with multiple axis
configuration. After upgrade navigating to project configuration page only
paints page until "Combination filter" section and then displays "Status code
null Exception Stacktrace: (null)".

Hudson master JVM displays a Winstone exception:

[Winstone 2009/05/07 10:33:36] - Untrapped Error in Servlet
org.apache.commons.jelly.JellyTagException: jar:file:/export/ciBuilder/Hudson/
war/WEB-INF/lib/hudson-core-1.303.jar!/lib/hudson/project/config-
buildWrappers.jelly:29:71: <j:set> hudson/maven/MavenModuleSet

followed by this exception:

javax.servlet.ServletException: jar:file:/export/ciBuilder/Hudson/war/WEB-INF/
lib/hudson-core-1.303.jar!/lib/hudson/project/config-buildWrappers.jelly:29:71:
<j:set> hudson/maven/MavenModuleSet

(will attach full exceptions and config files to this issue as files)