NPE when moving JAX-RS resource into another package

Stacktrace is :
java.lang.NullPointerException
at org.jboss.tools.ws.jaxrs.core.jdt.JdtUtils.resolveMethodSignature(JdtUtils.java:587)
at org.jboss.tools.ws.jaxrs.core.internal.metamodel.domain.JaxrsElementFactory.internalCreateResourceMethod(JaxrsElementFactory.java:236)
at org.jboss.tools.ws.jaxrs.core.internal.metamodel.domain.JaxrsElementFactory.createResource(JaxrsElementFactory.java:148)
at org.jboss.tools.ws.jaxrs.core.internal.metamodel.builder.JavaElementChangedProcessor.processAddition(JavaElementChangedProcessor.java:197)
at org.jboss.tools.ws.jaxrs.core.internal.metamodel.builder.JavaElementChangedProcessor.processAffectedElement(JavaElementChangedProcessor.java:122)
at org.jboss.tools.ws.jaxrs.core.internal.metamodel.builder.JavaElementChangedProcessor.processAffectedJavaElements(JavaElementChangedProcessor.java:75)
at org.jboss.tools.ws.jaxrs.core.internal.metamodel.builder.JavaElementChangedBuildJob.run(JavaElementChangedBuildJob.java:56)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)