Problem with HP ProCurve NAC 800

[Smasher]

Hello. I have troubles with NAC 800. During initial setup, after creating admin account I get internal error:

An internal error occurred while processing your request:

javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
	at com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Alerts.java:150)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1518)
	at com.sun.net.ssl.internal.ssl.Handshaker.fatalSE(Handshaker.java:174)
	at com.sun.net.ssl.internal.ssl.Handshaker.fatalSE(Handshaker.java:168)
	at com.sun.net.ssl.internal.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:848)
	at com.sun.net.ssl.internal.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:106)
	at com.sun.net.ssl.internal.ssl.Handshaker.processLoop(Handshaker.java:495)
	at com.sun.net.ssl.internal.ssl.Handshaker.process_record(Handshaker.java:433)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:818)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1030)
	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.writeRecord(SSLSocketImpl.java:622)
	at com.sun.net.ssl.internal.ssl.AppOutputStream.write(AppOutputStream.java:59)
	at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65)
	at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:123)
	at org.apache.commons.httpclient.HttpConnection.flushRequestOutputStream(HttpConnection.java:827)
	at org.apache.commons.httpclient.HttpMethodBase.writeRequest(HttpMethodBase.java:1975)
	at org.apache.commons.httpclient.HttpMethodBase.execute(HttpMethodBase.java:993)
	at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:397)
	at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:170)
	at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:396)
	at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:324)
	at com.hp.procurve.web.servlets.LoginServlet.doSecurityCheck(LoginServlet.java:91)
	at com.hp.procurve.web.servlets.LoginServlet.doPost(LoginServlet.java:66)
	at com.hp.procurve.web.servlets.LoginServlet.doGet(LoginServlet.java:30)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
	at com.hp.procurve.web.servlets.LocaleFilter.doFilter(LocaleFilter.java:34)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
	at com.hp.procurve.web.servlets.SeaSurfFilter.doFilter(SeaSurfFilter.java:79)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
	at com.hp.procurve.web.servlets.PostDataFilter.doFilter(PostDataFilter.java:27)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
	at com.hp.procurve.web.servlets.Utf8Filter.doFilter(Utf8Filter.java:30)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:432)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:541)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
	at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
	at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
	at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
	at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
	at java.lang.Thread.run(Thread.java:595)
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
	at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:221)
	at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:145)
	at sun.security.validator.Validator.validate(Validator.java:203)
	at com.sun.net.ssl.internal.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:172)
	at com.sun.net.ssl.internal.ssl.JsseX509TrustManager.checkServerTrusted(SSLContextImpl.java:320)
	at com.sun.net.ssl.internal.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:841)
	... 49 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
	at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:236)
	at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:194)
	at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:216)
	... 54 more

 Next time when I am open management page I see Login and Password fields, but after trying to log in I get the same error.