我使用KeystoneJs v3获得了以下问题。
在Azure上托管，MongoLab托管数据库。我通过localhost上的KeystoneJs访问数据库时没有收到此错误
我对KeystoneJs，node和mongo很新鲜，所以如果之前已经多次询问并解决了这个问题，我会道歉。
Thu Feb 19 2015 21:23:13 GMT+0000 (Coordinated Universal Time): Unaught exception: Error: Error setting TTL index on collection : app_sessions
at D:\home\site\wwwroot\node_modules\connect-mongo\lib\connect-mongo.js:169:23
at D:\home\site\wwwroot\node_modules\connect-mongo\node_modules\mongodb\lib\mongodb\db.js:1482:46
at D:\home\site\wwwroot\node_modules\connect-mongo\node_modules\mongodb\lib\mongodb\db.js:1615:20
at D:\home\site\wwwroot\node_modules\connect-mongo\node_modules\mongodb\lib\mongodb\cursor.js:169:22
at D:\home\site\wwwroot\node_modules\connect-mongo\node_modules\mongodb\lib\mongodb\cursor.js:700:39
at Cursor.close (D:\home\site\wwwroot\node_modules\connect-mongo\node_modules\mongodb\lib\mongodb\cursor.js:989:5)
at Cursor.wrappedCursorClose [as close] (D:\home\site\wwwroot\node_modules\newrelic\lib\instrumentation\mongodb.js:226:20)
at commandHandler (D:\home\site\wwwroot\node_modules\connect-mongo\node_modules\mongodb\lib\mongodb\cursor.js:700:21)
at D:\home\site\wwwroot\node_modules\connect-mongo\node_modules\mongodb\lib\mongodb\db.js:1888:9
at Server.Base._callHandler (D:\home\site\wwwroot\node_modules\connect-mongo\node_modules\mongodb\lib\mongodb\connection\base.js:453:41)
at D:\home\site\wwwroot\node_modules\connect-mongo\node_modules\mongodb\lib\mongodb\connection\server.js:487:18
at MongoReply.parseBody (D:\home\site\wwwroot\node_modules\connect-mongo\node_modules\mongodb\lib\mongodb\responses\mongo_reply.js:68:5)
at null.<anonymous> (D:\home\site\wwwroot\node_modules\connect-mongo\node_modules\mongodb\lib\mongodb\connection\server.js:445:20)
at emit (events.js:95:17)
at null.<anonymous> (D:\home\site\wwwroot\node_modules\connect-mongo\node_modules\mongodb\lib\mongodb\connection\connection_pool.js:201:13)
at emit (events.js:98:17)