= bug description =

Simply opening http://jenkins.cloud.fedoraproject.org/ throws following error on me:

{{{
hudson.util.HudsonFailedToLoad: org.jvnet.hudson.reactor.ReactorException: java.io.IOException: Unable to read /var/lib/jenkins/config.xml
at hudson.WebAppMain$3.run(WebAppMain.java:234)
Caused by: org.jvnet.hudson.reactor.ReactorException: java.io.IOException: Unable to read /var/lib/jenkins/config.xml
at org.jvnet.hudson.reactor.Reactor.execute(Reactor.java:269)
at jenkins.InitReactorRunner.run(InitReactorRunner.java:44)
at jenkins.model.Jenkins.executeReactor(Jenkins.java:896)
at jenkins.model.Jenkins.(Jenkins.java:795)
at hudson.model.Hudson.(Hudson.java:82)
at hudson.model.Hudson.(Hudson.java:78)
at hudson.WebAppMain$3.run(WebAppMain.java:222)
Caused by: java.io.IOException: Unable to read /var/lib/jenkins/config.xml
at hudson.XmlFile.unmarshal(XmlFile.java:165)
at jenkins.model.Jenkins$17.run(Jenkins.java:2622)
at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:169)
at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:282)
at jenkins.model.Jenkins$7.runTask(Jenkins.java:885)
at org.jvnet.hudson.reactor.Reactor$2.run(Reactor.java:210)
at org.jvnet.hudson.reactor.Reactor$Node.run(Reactor.java:117)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:701)
Caused by: com.thoughtworks.xstream.converters.ConversionException: hudson.security.ProjectMatrixAuthorizationStrategy : hudson.security.ProjectMatrixAuthorizationStrategy
---- Debugging information ----
message : hudson.security.ProjectMatrixAuthorizationStrategy
cause-exception : com.thoughtworks.xstream.mapper.CannotResolveClassException
cause-message : hudson.security.ProjectMatrixAuthorizationStrategy
class : hudson.model.Hudson
required-type : hudson.model.Hudson
converter-type : hudson.util.RobustReflectionConverter
path : /hudson/authorizationStrategy
line number : 11
version : not available

at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:79)
at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:65)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:66)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:50)
at com.thoughtworks.xstream.core.TreeUnmarshaller.start(TreeUnmarshaller.java:134)
at com.thoughtworks.xstream.core.AbstractTreeMarshallingStrategy.unmarshal(AbstractTreeMarshallingStrategy.java:32)
at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1189)
at hudson.util.XStream2.unmarshal(XStream2.java:113)
at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1173)
at hudson.XmlFile.unmarshal(XmlFile.java:163)
... 9 more

Caused by: com.thoughtworks.xstream.mapper.CannotResolveClassException: hudson.security.ProjectMatrixAuthorizationStrategy
at com.thoughtworks.xstream.mapper.DefaultMapper.realClass(DefaultMapper.java:79)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.DynamicProxyMapper.realClass(DynamicProxyMapper.java:55)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.PackageAliasingMapper.realClass(PackageAliasingMapper.java:88)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.ClassAliasingMapper.realClass(ClassAliasingMapper.java:79)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.ArrayMapper.realClass(ArrayMapper.java:74)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.SecurityMapper.realClass(SecurityMapper.java:71)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at hudson.util.XStream2$CompatibilityMapper.realClass(XStream2.java:280)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at hudson.util.xstream.MapperDelegate.realClass(MapperDelegate.java:43)
at com.thoughtworks.xstream.mapper.MapperWrapper.realClass(MapperWrapper.java:30)
at com.thoughtworks.xstream.mapper.CachingMapper.realClass(CachingMapper.java:48)
at hudson.util.RobustReflectionConverter.determineType(RobustReflectionConverter.java:417)
at hudson.util.RobustReflectionConverter.doUnmarshal(RobustReflectionConverter.java:285)
at hudson.util.RobustReflectionConverter.unmarshal(RobustReflectionConverter.java:228)
at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:72)
... 18 more
}}}