When trying to restore from a Redis backup, there are a few reasons the restore will fail. I have listed the three I have found however there could be more:
1 – The backup was created from a large node and now you trying to restore to a smaller node.
2 – The bucket name. If the S3 bucket name has a multiple dots (.) which does not match cert *.s3.amazonaws.com, it will fail to restore. Certificates cannot match multiple wildcards, so there’s no way for us to have a *.*.*.s3.amazonaws.com cert.
3 – Bucket permissions.