We get when driver tries to serialize object id and when we try to toString object id created by the driver. It does not happen all the time. Currently we unable to reproduce it, but in production system we encounter it at least once an hour.

ObjectId in outgoing request

"error":"TypeError: Cannot read property 'copy' of undefined","message":"TypeError: Cannot read property 'copy' of undefined
at serializeObjectId (/somewhere/node_modules/bson/lib/bson/parser/serializer.js:252:13)
at serializeInto (/somewhere/node_modules/bson/lib/bson/parser/serializer.js:725:17)
at serializeObject (/somewhere/node_modules/bson/lib/bson/parser/serializer.js:291:18)
at serializeInto (/somewhere/node_modules/bson/lib/bson/parser/serializer.js:731:17)
at serialize (/somewhere/node_modules/bson/lib/bson/bson.js:48:27)
at Query.toBin (/somewhere/node_modules/mongodb-core/lib/connection/commands.js:143:25)
at Server.command (/somewhere/node_modules/mongodb-core/lib/topologies/server.js:493:27)
at ReplSet.command (/somewhere/node_modules/mongodb-core/lib/topologies/replset.js:1045:10)
at ReplSet.command (/somewhere/node_modules/mongodb/lib/replset.js:386:18)
at executeCommand (/somewhere/node_modules/mongodb/lib/db.js:307:19)
at Db.command (/somewhere/node_modules/mongodb/lib/db.js:331:44)
at findAndModify (/somewhere/node_modules/mongodb/lib/collection.js:2456:13)
at Collection.findAndModify (/somewhere/node_modules/mongodb/lib/collection.js:2391:44)
at findOneAndUpdate (/somewhere/node_modules/mongodb/lib/collection.js:2347:8)
at Collection.findOneAndUpdate (/somewhere/node_modules/mongodb/lib/collection.js:2325:44)
at VisitorSessions.Datastore.findOneAndUpdate (/somewhere/node_modules/tawk-mongodb-manager/lib/datastore.js:137:18)

Object id incoming results

"error":"TypeError: Cannot read property 'length' of undefined","message":"TypeError: Cannot read property 'length' of undefined
at ObjectID.toHexString (/somewhere/node_modules/bson/lib/bson/objectid.js:77:30)
at ObjectID.toString (/somewhere/node_modules/bson/lib/bson/objectid.js:151:15)
at getPageId (/somewhere/node_modules/commons/models/pages.js:641:18)
at Array.map (native)
at collection.find.toArray (/somewhere/node_modules/commons/models/pages.js:719:38)
at handleCallback (/somewhere/node_modules/mongodb/lib/utils.js:96:12)
at /somewhere/node_modules/mongodb/lib/cursor.js:858:16
at handleCallback (/somewhere/node_modules/mongodb-core/lib/cursor.js:156:5)
at setCursorDeadAndNotified (/somewhere/node_modules/mongodb-core/lib/cursor.js:496:3)
at nextFunction (/somewhere/node_modules/mongodb-core/lib/cursor.js:640:7)
at Cursor.next [as _next] (/somewhere/node_modules/mongodb-core/lib/cursor.js:681:3)
at fetchDocs (/somewhere/node_modules/mongodb/lib/cursor.js:853:10)
at /somewhere/node_modules/mongodb/lib/cursor.js:877:7
at handleCallback (/somewhere/node_modules/mongodb-core/lib/cursor.js:156:5)
at nextFunction (/somewhere/node_modules/mongodb-core/lib/cursor.js:671:5)
at /somewhere/node_modules/mongodb-core/lib/cursor.js:582:7
at Object.queryCallback [as cb] (/somewhere/node_modules/mongodb-core/lib/cursor.js:217:18)
at /somewhere/node_modules/mongodb-core/lib/connection/pool.js:446:18
at authenticateStragglers (/somewhere/node_modules/mongodb-core/lib/connection/pool.js:402:16)
at .messageHandler (/somewhere/node_modules/mongodb-core/lib/connection/pool.js:424:5)
at Socket.<anonymous> (/somewhere/node_modules/mongodb-core/lib/connection/connection.js:294:22)
at emitOne (events.js:96:13)
at Socket.emit (events.js:188:7)
at readableAddChunk (_stream_readable.js:177:18)
at Socket.Readable.push (_stream_readable.js:135:10)
at TCP.onread (net.js:542:20)"

It seems sometimes object id does not have id property