MongooseError: Schema hasn't been registered for model "Report"

mode_register_error.js

// need to require the reports.js(schema file in model) in db connect file

[nodemon] restarting due to changes...
[nodemon] starting `node ./bin/www`
(node:26035) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 exit listeners added. Use emitter.setMaxListeners() to increase limit

/home/sheng/Work/smr_pjt_loct_dr/node_modules/mongoose/lib/index.js:382
      throw new mongoose.Error.MissingSchemaError(name);
      ^
MongooseError: Schema hasn't been registered for model "Report".
Use mongoose.model(name, schema)
    at Mongoose.model (/home/sheng/Work/smr_pjt_loct_dr/node_modules/mongoose/lib/index.js:382:13)
    at Object.<anonymous> (/home/sheng/Work/smr_pjt_loct_dr/app_api/controllers/reports.js:2:23)
    at Module._compile (module.js:571:32)
    at Object.Module._extensions..js (module.js:580:10)
    at Module.load (module.js:488:32)
    at tryModuleLoad (module.js:447:12)
    at Function.Module._load (module.js:439:3)
    at Module.require (module.js:498:17)
    at require (internal/module.js:20:19)
    at Object.<anonymous> (/home/sheng/Work/smr_pjt_loct_dr/app_api/routes/index.js:6:19)
    at Module._compile (module.js:571:32)
    at Object.Module._extensions..js (module.js:580:10)
    at Module.load (module.js:488:32)
    at tryModuleLoad (module.js:447:12)
    at Function.Module._load (module.js:439:3)
    at Module.require (module.js:498:17)
[nodemon] app crashed - waiting for file changes before starting...