org.apache.mina.filter.codec.ProtocolEncoderException: java.lang.NullPointerException

java.lang.NullPointerException: 	at org.apache.directory.api.ldap.codec.decorators.SearchRequestDecorator.computeLength(SearchRequestDecorator.java:927)	at org.apache.directory.api.ldap.codec.api.LdapEncoder.computeMessageLength(LdapEncoder.java:248)	at org.apache.directory.api.ldap.codec.api.LdapEncoder.encodeMessage(LdapEncoder.java:160)	at org.apache.directory.api.ldap.codec.protocol.mina.LdapProtocolEncoder.encode(LdapProtocolEncoder.java:78)	at org.apache.mina.filter.codec.ProtocolCodecFilter.filterWrite(ProtocolCodecFilter.java:306)	at org.apache.mina.core.filterchain.DefaultIoFilterChain.callPreviousFilterWrite(DefaultIoFilterChain.java:625)	at org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1500(DefaultIoFilterChain.java:48)	at org.apache.mina.core.filterchain.DefaultIoFilterChain$EntryImpl$1.filterWrite(DefaultIoFilterChain.java:953)	at org.apache.mina.core.filterchain.DefaultIoFilterChain$TailFilter.filterWrite(DefaultIoFilterChain.java:877)	at org.apache.mina.core.filterchain.DefaultIoFilterChain.callPreviousFilterWrite(DefaultIoFilterChain.java:625)	at org.apache.mina.core.filterchain.DefaultIoFilterChain.fireFilterWrite(DefaultIoFilterChain.java:618)	at org.apache.mina.core.session.AbstractIoSession.write(AbstractIoSession.java:502)	at org.apache.mina.core.session.AbstractIoSession.write(AbstractIoSession.java:447)	at org.apache.directory.ldap.client.api.LdapNetworkConnection.writeRequest(LdapNetworkConnection.java:4073)	at org.apache.directory.ldap.client.api.LdapNetworkConnection.searchAsync(LdapNetworkConnection.java:1752)	at org.apache.directory.ldap.client.api.LdapNetworkConnection.search(LdapNetworkConnection.java:1778)	at org.apache.directory.ldap.client.api.LdapNetworkConnection.search(LdapNetworkConnection.java:1671)	at org.apache.directory.ldap.client.api.LdapNetworkConnection.search(LdapNetworkConnection.java:1681)	at org.graylog2.security.ldap.LdapConnector.search(LdapConnector.java:133)	at org.graylog2.rest.resources.system.ldap.LdapResource.testLdapConfiguration(LdapResource.java:168)	at sun.reflect.GeneratedMethodAccessor193.invoke(Unknown Source)	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)	at java.lang.reflect.Method.invoke(Method.java:498)	at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory$1.invoke(ResourceMethodInvocationHandlerFactory.java:81)	at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:144)	at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:161)	at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$TypeOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:205)	at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:99)	at org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:389)	at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:347)	at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:102)	at org.glassfish.jersey.server.ServerRuntime$2.run(ServerRuntime.java:326)	at org.glassfish.jersey.internal.Errors$1.call(Errors.java:271)	at org.glassfish.jersey.internal.Errors$1.call(Errors.java:267)	at org.glassfish.jersey.internal.Errors.process(Errors.java:315)	at org.glassfish.jersey.internal.Errors.process(Errors.java:297)	at org.glassfish.jersey.internal.Errors.process(Errors.java:267)	at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:317)	at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:305)	at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:1154)	at org.glassfish.jersey.grizzly2.httpserver.GrizzlyHttpContainer.service(GrizzlyHttpContainer.java:384)	at org.glassfish.grizzly.http.server.HttpHandler$1.run(HttpHandler.java:224)	at com.codahale.metrics.InstrumentedExecutorService$InstrumentedRunnable.run(InstrumentedExecutorService.java:176)	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)	at java.lang.Thread.run(Thread.java:745)