Describes the cause and action for error messages.
Error Message(English)：
invalid principal
AWS Developer Forums: S3 bucket policyのPrincipalにIAM ...
https://forums.aws.amazon.com/thread.jspa?threadID=86648
Bucket PolicyでPrincipalにIAM Groupが指定できない | AWSコスト削減 ...
https://www.simpline.co.jp/tech_ty/bucket-policy%E3%81%A7principal%E3%81%ABiam-group%E3%81%8C%E6%8C%・・・
[AWS] S3バケットポリシーで、特定のIAMロールだけがバケットにアクセス ...
https://qiita.com/n-ishida/items/33cef1d67adc0961625a
amazon s3 invalid principal in bucket policy - Stack Overflow
https://stackoverflow.com/questions/12750065/amazon-s3-invalid-principal-in-bucket-policy
s3 bucket policy saying invalid principal in policy but same ...
https://stackoverflow.com/questions/54186301/s3-bucket-policy-saying-invalid-principal-in-policy-but・・・
Error Invalid principal in policy?
https://stackoverflow.com/questions/45830203/error-invalid-principal-in-policy
Invalid principal in policy
https://stackoverflow.com/questions/37615891/invalid-principal-in-policy
AWS s3 bucket policy invalid group principal
https://stackoverflow.com/questions/17063868/aws-s3-bucket-policy-invalid-group-principal
S3 Bucket Policy - cannot add an IAM role as principal? : aws - Reddit
https://www.reddit.com/r/aws/comments/74o7te/s3_bucket_policy_cannot_add_an_iam_role_as/