Gruñido de Yeoman no pudo conectarse a MongoDB

He estado intentando ejecutar una aplicación generada por Yeoman, pero cada vez que ejecuto el grunt comando, me encuentro con el mismo error:

 PS C:\Users\Aiden\yo\mean> grunt Loading "grunt-karma.js" tasks...ERROR >> TypeError: Cannot read property 'prototype' of undefined >> Local Npm module "grunt-node-inspector" not found. Is it installed? Running "env:dev" (env) task Running "sass:dist" (sass) task Warning: You need to have Ruby and Sass installed and in your PATH for this task to work. More info: https://github.com/gruntjs/grunt-contrib-sass Used --force, continuing. Running "less:dist" (less) task Running "jshint:all" (jshint) task >> 87 files lint free. Running "csslint:all" (csslint) task >> 2 files lint free. Running "mkdir:upload" task Running "copy:localConfig" (copy) task Running "concurrent:default" (concurrent) task Loading "grunt-karma.js" tasks...ERROR >> TypeError: Cannot read property 'prototype' of undefined Loading "grunt-karma.js" tasks...ERROR >> TypeError: Cannot read property 'prototype' of undefined >> Local Npm module "grunt-node-inspector" not found. Is it installed? >> Local Npm module "grunt-node-inspector" not found. Is it installed? Running "watch" task Waiting... Running "nodemon:dev" (nodemon) task [nodemon] 1.11.0 [nodemon] to restart at any time, enter `rs` [nodemon] watching: server.js config/**/*.js modules/*/server/**/*.js [nodemon] starting `node --debug server.js` (node:8744) DeprecationWarning: node --debug is deprecated. Please use node --inspect instead. Debugger listening on 127.0.0.1:5858 Could not connect to MongoDB! { MongoError: failed to connect to server [localhost:27017] on first connect [MongoError: connect ECONNREFUSED 127.0.0.1:27017] at Pool. (C:\Users\Aiden\yo\mean\node_modules\mongoose\node_modules\mongodb-core\lib\topologies\server.js:328:35) at emitOne (events.js:96:13) at Pool.emit (events.js:191:7) at Connection. (C:\Users\Aiden\yo\mean\node_modules\mongoose\node_modules\mongodb- core\lib\connection\pool.js:274:1 2) at Object.onceWrapper (events.js:293:19) at emitTwo (events.js:106:13) at Connection.emit (events.js:194:7) at Socket. (C:\Users\Aiden\yo\mean\node_modules\mongoose\node_modules\mongodb- core\lib\connection\connection.js:177 :49) at Object.onceWrapper (events.js:293:19) at emitOne (events.js:96:13) at Socket.emit (events.js:191:7) at emitErrorNT (net.js:1279:8) at _combinedTickCallback (internal/process/next_tick.js:80:11) at process._tickCallback (internal/process/next_tick.js:104:9) name: 'MongoError', message: 'failed to connect to server [localhost:27017] on first connect [MongoError: connect ECONNREFUSED 127.0.0.1:27017]' } C:\Program Files\nodejs\node.exe: src\debug-agent.cc:147: Assertion `(err) == (0)' failed. [nodemon] app crashed - waiting for file changes before starting... 

He probado todas las soluciones que pude encontrar con respecto a este problema, incluida la instalación de al menos una docena de paquetes diferentes utilizando NPM. Estoy en una pérdida. ¿Algunas ideas?