/node_modules/mongodb/node_modules/mongodb-core/lib/topologies/server.js:766 catch(err) { process.nextTick(function() { throw err}); } ^ TypeError: Cannot read property 'name' of undefined at Server.equals (/node_modules/mongodb/node_modules/mongodb-core/lib/topologies/server.js:1081:16) at State.isPrimary (/node_modules/mongodb/node_modules/mongodb-core/lib/topologies/replset_state.js:71:39) at State.update (/node_modules/mongodb/node_modules/mongodb-core/lib/topologies/replset_state.js:404:69) at /node_modules/mongodb/node_modules/mongodb-core/lib/topologies/replset.js:1001:27 at /node_modules/mongodb/node_modules/mongodb-core/lib/topologies/server.js:765:13 at Callbacks.emit (/node_modules/mongodb/node_modules/mongodb-core/lib/topologies/server.js:95:3) at null.messageHandler (/node_modules/mongodb/node_modules/mongodb-core/lib/topologies/server.js:243:23) at Socket. (/node_modules/mongodb/node_modules/mongodb-core/lib/connection/connection.js:262:22) at Socket.emit (events.js:95:17) at Socket. (_stream_readable.js:765:14)