这个怎么解决呀，各位大神们 

 Error: Uncaught, unspecified "error" event. ([object Object])    

at NativeConnection.emit (events.js:166:17)     

at Immediate.(F:\node\Imooc\node_modules\mongoose\lib\connec tion.js:322:19)   

.....

 [nodemon] app crashed - waiting for file changes before starting...