Internal Server Error

java.lang.IllegalStateException: javax.xml.stream.XMLStreamException: Illegal input: comment content has embedded -- in it (index 319)
	at info.textgrid.services.aggregator.teicorpus.TEICorpusSerializer.writeSkip(TEICorpusSerializer.java:295)
	at info.textgrid.services.aggregator.teicorpus.TEICorpusSerializer.walk(TEICorpusSerializer.java:145)
	at info.textgrid.services.aggregator.tree.AggregationTreeWalker.walkAggregation(AggregationTreeWalker.java:118)
	at info.textgrid.services.aggregator.teicorpus.TEICorpusSerializer.walkAggregation(TEICorpusSerializer.java:184)
	at info.textgrid.services.aggregator.tree.AggregationTreeWalker.walk(AggregationTreeWalker.java:58)
	at info.textgrid.services.aggregator.teicorpus.TEICorpusSerializer.walk(TEICorpusSerializer.java:138)
	at info.textgrid.services.aggregator.teicorpus.TEICorpusSerializer.write(TEICorpusSerializer.java:119)
	at info.textgrid.services.aggregator.teicorpus.CorpusBasedExporter.loadSource(CorpusBasedExporter.java:136)
	at info.textgrid.services.aggregator.html.HTMLWriter.getSource(HTMLWriter.java:212)
	at info.textgrid.services.aggregator.html.HTMLWriter.createResponse(HTMLWriter.java:312)
	at info.textgrid.services.aggregator.REST.getHTML(REST.java:152)
	at sun.reflect.GeneratedMethodAccessor69.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.cxf.service.invoker.AbstractInvoker.performInvocation(AbstractInvoker.java:179)
	at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:96)
	at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:201)
	at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:104)
	at org.apache.cxf.interceptor.ServiceInvokerInterceptor$1.run(ServiceInvokerInterceptor.java:59)
	at org.apache.cxf.interceptor.ServiceInvokerInterceptor.handleMessage(ServiceInvokerInterceptor.java:96)
	at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:307)
	at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:121)
	at org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:267)
	at org.apache.cxf.transport.servlet.ServletController.invokeDestination(ServletController.java:234)
	at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:208)
	at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:160)
	at org.apache.cxf.transport.servlet.CXFNonSpringServlet.invoke(CXFNonSpringServlet.java:225)
	at org.apache.cxf.transport.servlet.AbstractHTTPServlet.handleRequest(AbstractHTTPServlet.java:304)
	at org.apache.cxf.transport.servlet.AbstractHTTPServlet.doGet(AbstractHTTPServlet.java:222)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:529)
	at org.apache.cxf.transport.servlet.AbstractHTTPServlet.service(AbstractHTTPServlet.java:279)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:199)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:144)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:168)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:144)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:168)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:482)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:130)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93)
	at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:660)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:346)
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:396)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:937)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1793)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52)
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1190)
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:63)
	at java.lang.Thread.run(Thread.java:750)
Caused by: javax.xml.stream.XMLStreamException: Illegal input: comment content has embedded -- in it (index 319)
	at com.ctc.wstx.sw.BaseStreamWriter.throwOutputError(BaseStreamWriter.java:1596)
	at com.ctc.wstx.sw.BaseStreamWriter.throwOutputError(BaseStreamWriter.java:1603)
	at com.ctc.wstx.sw.BaseStreamWriter.reportNwfContent(BaseStreamWriter.java:1649)
	at com.ctc.wstx.sw.BaseStreamWriter.writeComment(BaseStreamWriter.java:510)
	at org.codehaus.stax2.ri.Stax2EventWriterImpl.add(Stax2EventWriterImpl.java:137)
	at info.textgrid.services.aggregator.teicorpus.TEICorpusSerializer.writeSkip(TEICorpusSerializer.java:292)
	... 52 more