A critical error on W3C Unicorn validator

When I use the W3C Unicorn validator on my web site (http;//www.rec-sec.com/) I get a critical error. Note that I used this validator many times in the past, I don’t know what went wrong.
Here’s the stack trace Unicorn returns:

class java.net.ProtocolException
Server redirected too many  times (20)
sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1451)
java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:379)
org.w3c.unicorn.input.URIInputParameter.check(URIInputParameter.java:115)
org.w3c.unicorn.UnicornCall.check(UnicornCall.java:85)
org.w3c.unicorn.action.ObserveAction.doGet(ObserveAction.java:279)
javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve..java:213)
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve..java:172)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:433)
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:174)
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:874)
org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
java.lang.Thread.run(Thread.java:662)


Please update me on this error or how to solve it.
Thank you, Moshe Ben Abu.