exception when starting MMS WebRTC

gistfile1.txt

15:12:28,784 INFO  [MGCP] Controller stopped
15:12:28,784 INFO  [MGCP] Set scheduler: null
15:12:28,785 INFO  [MGCP] Set server
15:12:28,787 INFO  [Server] Stopping UDP Manager
15:12:28,787 INFO  [UdpManager] Stopped
15:12:28,787 INFO  [Server] Stopping scheduler
15:12:28,827 INFO  [Server] Stopped media server instance 
Exception in thread "main" java.lang.IllegalStateException: SystemClock is already installed.
	at org.jboss.dependency.plugins.AbstractController.install(AbstractController.java:716)
	at org.jboss.dependency.plugins.AbstractController.install(AbstractController.java:540)
	at org.jboss.kernel.plugins.deployment.AbstractKernelDeployer.deployBean(AbstractKernelDeployer.java:319)
	at org.jboss.kernel.plugins.deployment.AbstractKernelDeployer.deployBeans(AbstractKernelDeployer.java:297)
	at org.jboss.kernel.plugins.deployment.AbstractKernelDeployer.deploy(AbstractKernelDeployer.java:130)
	at org.jboss.kernel.plugins.deployment.BasicKernelDeployer.deploy(BasicKernelDeployer.java:76)
	at org.jboss.kernel.plugins.deployment.xml.BasicXMLDeployer.deploy(BasicXMLDeployer.java:88)
	at org.jboss.kernel.plugins.deployment.xml.BasicXMLDeployer.deploy(BasicXMLDeployer.java:158)
	at org.mobicents.media.server.bootstrap.MainDeployer.start(MainDeployer.java:126)
	at org.mobicents.media.server.bootstrap.Main.start(Main.java:242)
	at org.mobicents.media.server.bootstrap.Main.boot(Main.java:235)
	at org.mobicents.media.server.bootstrap.Main.main(Main.java:86)