What Would Cause this Error?

Exception in thread "SwiftMQ-ConnectorPool-18" java.lang.IllegalStateException: Timer already cancelled.
 at java.util.Timer.sched(Unknown Source)
 at java.util.Timer.schedule(Unknown Source)
 at com.swiftmq.tools.timer.TimerRegistry.addTimerListener(Unknown Source)
 at com.swiftmq.jms.v750.Connector.writeObject(Unknown Source)
 at com.swiftmq.jms.v750.Connector.visit(Unknown Source)
 at com.swiftmq.jms.v750.po.POVersionRequest.accept(Unknown Source)
 at com.swiftmq.tools.pipeline.PipelineQueue.process(Unknown Source)
 at com.swiftmq.tools.queue.SingleProcessorQueue.dequeue(Unknown Source)
 at com.swiftmq.tools.pipeline.PipelineQueue$QueueProcessor.run(Unknown Source)
 at com.swiftmq.client.thread.PoolExecutor.run(Unknown Source)