Occasionally, AWS users may initially configure the SoftNAS product to use an Access Key/Secret Key pair as credentials for SoftNAS to interact with the AWS platform (see: AWS Getting Started - Creating Your AWS Access Key and Secret Access Key), but later decide to instead use an IAM role that is assigned to the instance(s) running SoftNAS (see: AWS Getting Started - Creating Your IAM role).
When the original configuration with the Access Key and Secret Key is chosen, the result will be to create a file to store these on your instance, called /root/.aws/credentials.
In this somewhat unusual case, when the IAM role is assigned to your SoftNAS instance(s), take the following action in order to avoid any conflict in permissions.
Rename this credentials file, as shown:
Alternatively, simply remove the credentials file, as shown:
rm credentials