CodePipeline失败,显示“操作失败,因为找不到工件或Amazon S3存储桶。”

我有以下管道定义:

  Pipeline:
    Type: 'AWS::CodePipeline::Pipeline'
    Properties:
       Name: !Ref AppName
       RoleArn: {"Fn::GetAtt" : ["PipelineServiceRole", "Arn"] }
       ArtifactStore:
          Type: S3
          Location: !Ref ArtifactBucket
       Stages: 
        - 
          Name: Source
          Actions: 
            - 
              Name: SourceAction
              ActionTypeId: 
                Category: Source
                Owner: AWS
                Version: 1
                Provider: S3
              OutputArtifacts: 
                - Name: "PipelineArtifact"
              Configuration: 
                S3Bucket: !Ref ArtifactBucket
                S3ObjectKey: !Ref ArtifactName
                PollForSourceChanges: true
              RunOrder: 1
        - 
          Name: Deploy
          Actions: 
            - 
              Name: DeployAction
              ActionTypeId: 
                Category: Deploy
                Owner: AWS
                Version: 1
                Provider: ElasticBeanstalk
              InputArtifacts: 
                - Name: "PipelineArtifact"
              Configuration:
                ApplicationName: !Ref EbApplication
                EnvironmentName: !Ref EbEnvironment

源阶段已成功完成,但在部署阶段出现以下错误:

我已经检查了工件是否在S3中的预期位置,以及PipelineServiceRole是否具有完全权限(字面意思是 */* ).

是什么导致了这个错误?