I got the following assertion failure when trying to call Trees.instance from a TaskListener.

An exception has occurred in the compiler ($(RELEASE)). Please file a bug at the Java Developer Connection (http://java.sun.com/webapps/bugreport) after checking the Bug Parade for duplicates. Include your program and the following diagnostic in your report. Thank you.
java.lang.AssertionError: FileManager initialization error
at com.sun.tools.javac.jvm.ClassReader.<init>(ClassReader.java:201)
at com.sun.tools.javac.jvm.ClassReader.instance(ClassReader.java:160)
at com.sun.tools.javac.comp.Enter.<init>(Enter.java:108)
at com.sun.tools.javac.comp.Enter.instance(Enter.java:99)
at com.sun.tools.javac.api.JavacTrees.<init>(JavacTrees.java:65)
at com.sun.tools.javac.api.JavacTrees.instance(JavacTrees.java:59)
at com.sun.tools.javac.api.JavacTrees.instance(JavacTrees.java:49)
at com.sun.tools.javac.api.Trees.instance(Trees.java:40)
at javacviewer.TaskState.started(TaskState.java:106)
at javacviewer.MainPanel$MainTaskListener.started(MainPanel.java:350)
at com.sun.tools.javac.main.JavaCompiler.parse(JavaCompiler.java:437)
at com.sun.tools.javac.main.JavaCompiler.parse(JavaCompiler.java:480)
at com.sun.tools.javac.main.JavaCompiler.parseFiles(JavaCompiler.java:697)
at com.sun.tools.javac.processing.JavacProcessingEnvironment.doProcessing(JavacProcessingEnvironment.java:609)
at com.sun.tools.javac.main.JavaCompiler.processAnnotations(JavaCompiler.java:844)
at com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:629)
at com.sun.tools.javac.main.Main.compile(Main.java:761)
at com.sun.tools.javac.api.JavacTaskImpl.run(JavacTaskImpl.java:82)
at javacviewer.MainPanel$RunAction.run(MainPanel.java:517)
at javacviewer.MainPanel$AsyncAction$1.run(MainPanel.java:445)