java.lang.UnsupportedOperationException
   at java.util.AbstractMap.put(AbstractMap.java:186)
   at org.netbeans.api.java.project.runner.JavaRunner.execute(JavaRunner.java:0)
   at org.netbeans.modules.maven.cos.CosChecker.cleanGeneratedClassfiles(CosChecker.java:568)
   at org.netbeans.modules.maven.cos.CosChecker.checkRunConfig(CosChecker.java:153)
   at org.netbeans.modules.maven.execute.MavenCommandLineExecutor.run(MavenCommandLineExecutor.java:137)
   at org.netbeans.core.execution.RunClassThread.run(RunClassThread.java:153)