### Environment

* Dubbo version: 2.7.6-SNAPSHOT
* Operating System version: Mac
* Java version: 1.8

### Steps to reproduce this issue

run dubbo-samples-simplified-registry-xml 

org.apache.dubbo.samples.simplified.registry.xml.DemoServiceIT
### Expected Result

should pass

### Actual Result

throw exception
} catch (Exception e) {
                            logger.warn("destroy invoker[" + invoker.getUrl() + "] failed. " + e.getMessage(), e);
                        }
                    }
                }
            }
        }
    }
    @Override
    public List<Invoker<T>> doList(Invocation invocation) {
        if (forbidden) {
            
            throw new RpcException(RpcException.FORBIDDEN_EXCEPTION, "No provider available from registry " +
                    getUrl().getAddress() + " for service " + getConsumerUrl().getServiceKey() + " on consumer " +
                    NetUtils.getLocalHost() + " use dubbo version " + Version.getVersion() +
                    ", please check status of providers(disabled, not registered or in blacklist).");
        }
        if (multiGroup) {
            return this.invokers == null ? Collections.emptyList() : this.invokers;
        }
        List<Invoker<T>> invokers = null;
        try {
            
            invokers = routerChain.route(getConsumerUrl(), invocation);
        } catch (Throwable t) {
            logger.error("Failed to execute router: " + getUrl() + ", cause: " + t.getMessage(), t);
        }
        return invokers == null ? Collections.emptyList() : invokers;
    }
    @Override