Erro ao alterar um objeto

Método de remoção o objeto:

Já tentei descobrir e não consegui.

@Transactional
public class BaseRepositorio<T> {

	@PersistenceContext
	private EntityManager entityManager;

	public EntityManager getEntityManager() {
		return entityManager;
	}

	public void setEntityManager(EntityManager entityManager) {
		this.entityManager = entityManager;
	}

	public T alterar(T objeto) {
		return this.entityManager.merge(objeto);
	}
}

Exception

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is javax.persistence.OptimisticLockException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect) : [br.com.netsoft.desif.model.endereco.PaisEntity#72]
	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:982)
	org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
	org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

Root Cause

javax.persistence.OptimisticLockException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect) : [br.com.netsoft.desif.model.endereco.PaisEntity#72]
	org.hibernate.internal.ExceptionConverterImpl.wrapStaleStateException(ExceptionConverterImpl.java:197)
	org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:86)
	org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:155)
	org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:162)
	org.hibernate.internal.SessionImpl.fireMerge(SessionImpl.java:878)
	org.hibernate.internal.SessionImpl.merge(SessionImpl.java:852)
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	java.lang.reflect.Method.invoke(Unknown Source)
	org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:298)
	com.sun.proxy.$Proxy244.merge(Unknown Source)
	br.com.netsoft.desif.repositorio.BaseRepositorio.alterar(BaseRepositorio.java:43)
	br.com.netsoft.desif.repositorio.BaseRepositorio$$FastClassBySpringCGLIB$$71b2a65a.invoke(<generated>)
	org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
	org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:738)
	org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
	org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
	org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282)
	org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
	org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
	org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:673)
	br.com.netsoft.desif.repositorio.endereco.PaisRepositorio$$EnhancerBySpringCGLIB$$d5ac8b59.alterar(<generated>)
	br.com.netsoft.desif.servico.endereco.PaisServico.salvar(PaisServico.java:30)
	br.com.netsoft.desif.controller.endereco.PaisController.salvar(PaisController.java:51)
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	java.lang.reflect.Method.invoke(Unknown Source)
	org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
	org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133)
	org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97)
	org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
	org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
	org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
	org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
	org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
	org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
	org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)


javax.persistence.OptimisticLockException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect) : [br.com.netsoft.desif.model.endereco.PaisEntity#72]
	org.hibernate.internal.ExceptionConverterImpl.wrapStaleStateException(ExceptionConverterImpl.java:197)
	org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:86)
	org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:155)
	org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:162)
	org.hibernate.internal.SessionImpl.fireMerge(SessionImpl.java:878)
	org.hibernate.internal.SessionImpl.merge(SessionImpl.java:852)
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	java.lang.reflect.Method.invoke(Unknown Source)
	org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:298)
	com.sun.proxy.$Proxy244.merge(Unknown Source)
	br.com.netsoft.desif.repositorio.BaseRepositorio.alterar(BaseRepositorio.java:43)
	br.com.netsoft.desif.repositorio.BaseRepositorio$$FastClassBySpringCGLIB$$71b2a65a.invoke(<generated>)
	org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
	org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:738)
	org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
	org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
	org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282)
	org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
	org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
	org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:673)
	br.com.netsoft.desif.repositorio.endereco.PaisRepositorio$$EnhancerBySpringCGLIB$$d5ac8b59.alterar(<generated>)
	br.com.netsoft.desif.servico.endereco.PaisServico.salvar(PaisServico.java:30)
	br.com.netsoft.desif.controller.endereco.PaisController.salvar(PaisController.java:51)
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	java.lang.reflect.Method.invoke(Unknown Source)
	org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
	org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133)
	org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97)
	org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
	org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
	org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
	org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
	org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
	org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
	org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

Root Cause

org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect) : [br.com.netsoft.desif.model.endereco.PaisEntity#72]
	org.hibernate.event.internal.DefaultMergeEventListener.entityIsDetached(DefaultMergeEventListener.java:322)
	org.hibernate.event.internal.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:170)
	org.hibernate.event.internal.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:69)
	org.hibernate.internal.SessionImpl.fireMerge(SessionImpl.java:866)
	org.hibernate.internal.SessionImpl.merge(SessionImpl.java:852)
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	java.lang.reflect.Method.invoke(Unknown Source)
	org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:298)
	com.sun.proxy.$Proxy244.merge(Unknown Source)
	br.com.netsoft.desif.repositorio.BaseRepositorio.alterar(BaseRepositorio.java:43)
	br.com.netsoft.desif.repositorio.BaseRepositorio$$FastClassBySpringCGLIB$$71b2a65a.invoke(<generated>)
	org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
	org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:738)
	org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
	org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
	org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282)
	org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
	org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
	org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:673)
	br.com.netsoft.desif.repositorio.endereco.PaisRepositorio$$EnhancerBySpringCGLIB$$d5ac8b59.alterar(<generated>)
	br.com.netsoft.desif.servico.endereco.PaisServico.salvar(PaisServico.java:30)
	br.com.netsoft.desif.controller.endereco.PaisController.salvar(PaisController.java:51)
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	java.lang.reflect.Method.invoke(Unknown Source)
	org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)
	org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133)
	org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97)
	org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
	org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
	org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
	org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
	org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
	org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
	org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
	org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)