Exception while invoking method 'saveUserProfile' MongoError: The positional operator did not find the match needed from the query. Unexpanded update: mentions.$.username     at Object.Future.wait (/app/bundle/programs/server/node_modules/fibers/future.js:398:15)     at [object Object].<anonymous> (packages/meteor/helpers.js:119:1)     at [object Object].MongoConnection.(anonymous function) [as update] (packages/mongo/mongo_driver.js:736:1)     at Object.CollectionHooks.defineAdvice.self (packages/matb33_collection-hooks/update.js:80:1)     at Object.collection.(anonymous function) [as update] (packages/matb33_collection-hooks/collection-hooks.js:117:1)     at [object Object].Mongo.Collection.(anonymous function) (packages/mongo/collection.js:590:1)     at [object Object].Mongo.Collection.(anonymous function) [as update] (packages/dispatch_run-as-user/packages/dispatch_run-as-user.js:300:1)     at _Class.update (server/models/_Base.js:78:29)     at _Class.RocketChat.models.Messages._Class.updateUsernameAndMessageOfMentionByIdAndOldUsername (packages/rocketchat_lib/server/models/Messages.coffee:231:11)     at packages/rocketchat_lib/server/functions/setUsername.coffee:40:31     - - - - -     at Object.toError (/app/bundle/programs/server/npm/npm-mongo/node_modules/mongodb/lib/mongodb/utils.js:114:11)     at /app/bundle/programs/server/npm/npm-mongo/node_modules/mongodb/lib/mongodb/collection/core.js:577:27     at /app/bundle/programs/server/npm/npm-mongo/node_modules/mongodb/lib/mongodb/db.js:1197:7     at /app/bundle/programs/server/npm/npm-mongo/node_modules/mongodb/lib/mongodb/db.js:1905:9     at Server.Base._callHandler (/app/bundle/programs/server/npm/npm-mongo/node_modules/mongodb/lib/mongodb/connection/base.js:453:41)     at /app/bundle/programs/server/npm/npm-mongo/node_modules/mongodb/lib/mongodb/connection/server.js:488:18     at [object Object].MongoReply.parseBody (/app/bundle/programs/server/npm/npm-mongo/node_modules/mongodb/lib/mongodb/responses/mongo_reply.js:68:5)     at [object Object].<anonymous> (/app/bundle/programs/server/npm/npm-mongo/node_modules/mongodb/lib/mongodb/connection/server.js:446:20)     at [object Object].emit (events.js:95:17)     at [object Object].<anonymous> (/app/bundle/programs/server/npm/npm-mongo/node_modules/mongodb/lib/mongodb/connection/connection_pool.js:207:13)