Site shows stacktrace about feeds

Accessing the site shows this error:

HTTP ERROR 500

Problem accessing /site/. Reason:

com.sun.syndication.io.SyndFeedInput.setPreserveWireFeed(Z)V

Caused by:

java.lang.NoSuchMethodError:
com.sun.syndication.io.SyndFeedInput.setPreserveWireFeed(Z)V
at com.sun.syndication.fetcher.impl.HttpClientFeedFetcher.retrieveFeed(HttpClientFeedFetcher.java:316)
at com.sun.syndication.fetcher.impl.HttpClientFeedFetcher.getFeed(HttpClientFeedFetcher.java:333)
at com.sun.syndication.fetcher.impl.HttpClientFeedFetcher.retrieveFeed(HttpClientFeedFetcher.java:211)
at com.onehippo.gogreen.utils.FeedFetcher.getSyndFeeds(FeedFetcher.java:87)
at com.onehippo.gogreen.utils.FeedFetcher.retrieveFeeds(FeedFetcher.java:68)
at com.onehippo.gogreen.components.Feeds.doBeforeRender(Feeds.java:55)
at org.hippoecm.hst.core.container.HstComponentInvokerImpl.invokeBeforeRender(HstComponentInvokerImpl.java:133)
at sun.reflect.GeneratedMethodAccessor28.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:309)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:80)
at org.hippoecm.hst.core.logging.HstComponentInvokerProfiler.profile(HstComponentInvokerProfiler.java:70)
at sun.reflect.GeneratedMethodAccessor27.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:621)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:610)
at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:65)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:89)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
at $Proxy0.invokeBeforeRender(Unknown Source)