Problem description
The value of the x-amz-credential header in the PostObject request is invalid.
Causes
You initiated a PostObject request that uses an Amazon S3-compatible V4 signature, but the value of the x-amz-credential header is invalid.
Examples
The x-amz-credential header in the following request contains only four fields. The x-amz-credential header must contain five fields that are separated by forward slashes (/).
Solutions
The x-amz-credential header must be in the following format: <YOUR-AKID>/YYYYMMDD/REGION/SERVICE/aws4_request. Make sure that the header is correctly specified.
For more information, see PostObject.