이러한 에러가 뜨는 이유는 먼가요 그리고 이미지를 올리면 계속 alert 문구가 뜹니다.

Server Listening on 5000 [0] { MongooseServerSelectionError: connection <monitor> to 54.144.208.74:27017 closed [0] at new MongooseServerSelectionError (C:\Users\Admin\boilerplate-mern-stack\node_modules\mongoose\lib\error\serverSelection.js:22:11) [0] at NativeConnection.Connection.openUri (C:\Users\Admin\boilerplate-mern-stack\node_modules\mongoose\lib\connection.js:823:32) [0] at Mongoose.connect (C:\Users\Admin\boilerplate-mern-stack\node_modules\mongoose\lib\index.js:333:15) [0] at Object.<anonymous> (C:\Users\Admin\boilerplate-mern-stack\server\index.js:19:4) [0] at Module._compile (internal/modules/cjs/loader.js:776:30) [0] at Object.Module._extensions..js (internal/modules/cjs/loader.js:787:10) [0] at Module.load (internal/modules/cjs/loader.js:653:32) [0] at tryModuleLoad (internal/modules/cjs/loader.js:593:12) [0] at Function.Module._load (internal/modules/cjs/loader.js:585:3) [0] at Function.Module.runMain (internal/modules/cjs/loader.js:829:12) [0] at startup (internal/bootstrap/node.js:283:19) [0] at bootstrapNodeJSCore (internal/bootstrap/node.js:622:3) [0] message: 'connection <monitor> to 54.144.208.74:27017 closed', [0] name: 'MongooseServerSelectionError', [0] reason: [0] TopologyDescription { [0] type: 'ReplicaSetNoPrimary', [0] setName: null, [0] maxSetVersion: null, [0] maxElectionId: null, [0] servers: [0] Map { [0] 'project-shard-00-00.hlpbc.mongodb.net:27017' => [ServerDescription], [0] 'project-shard-00-02.hlpbc.mongodb.net:27017' => [ServerDescription], [0] 'project-shard-00-01.hlpbc.mongodb.net:27017' => [ServerDescription] }, [0] stale: false, [0] compatible: true, [0] compatibilityError: null, [0] logicalSessionTimeoutMinutes: null, [0] heartbeatFrequencyMS: 10000, [0] localThresholdMS: 15, [0] commonWireVersion: null }, [0] [Symbol(mongoErrorContextSymbol)]: {} }