Jenkins ver. 1.564-SNAPSHOT (private-05/05/2014 19:11 GMT-jenkins)
I cannot load anymore a matrix project.
Stack says:

SEVERE: Failed Loading job Ant-Build-Matrix
groovy.lang.MissingPropertyException: No such property: hudson for class: Script1
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.unwrap(ScriptBytecodeAdapter.java:50)
at org.codehaus.groovy.runtime.callsite.PogoGetPropertySite.getProperty(PogoGetPropertySite.java:49)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callGroovyObjectGetProperty(AbstractCallSite.java:231)
at Script1.run(Script1.groovy:1)
at hudson.matrix.FilterScript.evaluate(FilterScript.java:36)
at hudson.matrix.FilterScript.apply(FilterScript.java:73)
at hudson.matrix.Combination.evalGroovyExpression(Combination.java:101)
at hudson.matrix.Combination.evalGroovyExpression(Combination.java:91)
at hudson.matrix.MatrixProject.rebuildConfigurations(MatrixProject.java:637)
at hudson.matrix.MatrixProject.onLoad(MatrixProject.java:504)
at hudson.model.Items.load(Items.java:273)
at jenkins.model.Jenkins$18.run(Jenkins.java:2592)
at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:169)
at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:282)
at jenkins.model.Jenkins$7.runTask(Jenkins.java:904)
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:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)