Could not create delegate Module[Seam_war,org.eclipse.jst.jee.server:Seam_war]

java.lang.NullPointerException
	at org.eclipse.wst.server.core.internal.Module.getDelegate(Module.java:117)
	at org.eclipse.wst.server.core.internal.Module.loadAdapter(Module.java:209)
	at org.jboss.ide.eclipse.as.core.server.internal.JBossServer.getChildModules(JBossServer.java:109)
	at org.eclipse.wst.server.core.internal.Server.getChildModules(Server.java:2289)
	at org.eclipse.wst.server.core.internal.Server.visitModule(Server.java:2449)
	at org.eclipse.wst.server.core.internal.Server.visit(Server.java:2430)
	at org.eclipse.wst.server.core.internal.Server$ResourceChangeJob.run(Server.java:188)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)