Невозможно получить элемент с индексом 2 из набора размера 2

Прежде всего, извините, если у меня есть ошибки в тексте, я плохо говорю по-английски. У меня есть таблица в JSP, которая показывает мне людей, работающих над патентом.

Здесь у вас есть код JSP.

<c:forEach items = "${newitem.inventors}" var = "inv" varStatus = "status">
                    <tr>
                        <input type = "hidden" name='<c:out value = "inventors[${status.index}].toDelete"/>' class = "toDelete" value=''/>
                        <input type = "hidden" name='<c:out value = "inventors[${status.index}].id"/>' value='<c:out value = "${inv.id}"/>'/> 
                        <td><input type = "text" name='<c:out value = "inventors[${status.index}].nom"/>' value='<c:out value = "${inv.nom}"/>'/> </td>
                        <td><input type = "text" name='<c:out value = "inventors[${status.index}].nif"/>' value='<c:out value = "${inv.nif}"/>'/> </td>
                        <td><input type = "text" name='<c:out value = "inventors[${status.index}].departament"/>' value='<c:out value = "${inv.departament}"/>'/> </td>
                        <td><input type = "text" name='<c:out value = "inventors[${status.index}].entitat"/>' value='<c:out value = "${inv.entitat}"/>'/> </td>
                        <td><input type = "text" name='<c:out value = "inventors[${status.index}].relacioLaboral"/>' value='<c:out value = "${inv.relacioLaboral}"/>'/> </td>
                        <td><input type = "text" name='<c:out value = "inventors[${status.index}].percent"/>' value='<c:out value = "${inv.percent}"/>'/> </td>
                        <td class = "inventorCheckBox">
                              <input type = "checkbox"/> 
                              <input type = "hidden" class = "textCheckBox" name='<c:out value = "inventors[${status.index}].responsable"/>'  value='<c:out value = "${inv.responsable}"/>' /> 
                        </td>
                        <td><input type = "text" name='<c:out value = "inventors[${status.index}].mail"/>' value='<c:out value = "${inv.mail}"/>'/> </td>
                        <td><input type = "text" name='<c:out value = "inventors[${status.index}].ordenacio"/>' value='<c:out value = "${inv.ordenacio}"/>'/> </td>
                        <td><span onclick = "deleteInventor(this);" style = "margin-left:15px;font-size:1.4em;cursor:pointer;" aria-hidden = "true" class = "colorLogo icon-close"></span></td>
                        <!--<td class = "inventorCheckBox">
                                <input type = "checkbox"/> 
                                <input type = "hidden"  class = "textCheckBox" name='<c:out value = "inventors[${status.index}].intern"/>' value='<c:out value = "${inv.intern}"/>'/> 
                        </td> -->
                    </tr>
        </c:forEach>

Теперь я внедряю функциональность, чтобы ДОБАВИТЬ больше людей. Эти люди хранятся в HashSet, чтобы позже ввести данные в базу данных. Прежде всего, я пытаюсь добавить людей, которые просто копируют 1 строку с помощью инспектора элементов и сохраняют, но когда я нажимаю, чтобы сохранить, это выдает мне эту ошибку.

GRAVE: El Servlet.service() para el servlet [pinney] en el contexto con ruta [/ideas] lanzó la excepción [Request processing failed; nested exception is org.springframework.beans.InvalidPropertyException: Invalid property 'inventors[2]' of bean class [com.gmv.pinney.vo.invencio.NovaInvencio]: Illegal attempt to get property 'inventors' threw exception; nested exception is org.springframework.beans.InvalidPropertyException: Invalid property 'inventors[2]' of bean class [com.gmv.pinney.vo.invencio.NovaInvencio]: Cannot get element with index 2 from Set of size 2, accessed using property path 'inventors[2]'] con causa raíz
org.springframework.beans.InvalidPropertyException: Invalid property 'inventors[2]' of bean class [com.gmv.pinney.vo.invencio.NovaInvencio]: Cannot get element with index 2 from Set of size 2, accessed using property path 'inventors[2]'
    at org.springframework.beans.BeanWrapperImpl.getPropertyValue(BeanWrapperImpl.java:806)
    at org.springframework.beans.BeanWrapperImpl.getNestedBeanWrapper(BeanWrapperImpl.java:572)
    at org.springframework.beans.BeanWrapperImpl.getBeanWrapperForPropertyPath(BeanWrapperImpl.java:549)
    at org.springframework.beans.BeanWrapperImpl.setPropertyValue(BeanWrapperImpl.java:917)
    at org.springframework.beans.AbstractPropertyAccessor.setPropertyValues(AbstractPropertyAccessor.java:95)
    at org.springframework.validation.DataBinder.applyPropertyValues(DataBinder.java:749)
    at org.springframework.validation.DataBinder.doBind(DataBinder.java:645)
    at org.springframework.web.bind.WebDataBinder.doBind(WebDataBinder.java:189)
    at org.springframework.web.bind.ServletRequestDataBinder.bind(ServletRequestDataBinder.java:106)
    at org.springframework.web.servlet.mvc.BaseCommandController.bindAndValidate(BaseCommandController.java:394)
    at org.springframework.web.servlet.mvc.AbstractFormController.handleRequestInternal(AbstractFormController.java:266)
    at com.gmv.pinney.web.forms.AbstractPinneyFormController.handleRequestInternal(AbstractPinneyFormController.java:54)
    at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:146)
    at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:50)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:868)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:316)
    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:126)
    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:90)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
    at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:114)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
    at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:122)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
    at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
    at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:168)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
    at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:48)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
    at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:205)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
    at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:120)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
    at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:64)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
    at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:53)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
    at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:91)
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
    at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:213)
    at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:176)
    at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:344)
    at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:261)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.filters.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:109)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:493)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:650)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:800)
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:800)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1471)
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:748)

Я не знаю, что мне делать, не могли бы вы мне помочь?

Спасибо за внимание