Amazon Search Error: RequestThrottled = AWS Access Key ID: xxxxxxxxxxxxxxxxx. You are submitting requests too quickly. Please retry your requests at a slower rate.
Amazon is disabling accounts that don't provide a referral sale within the previous month. This is the error they used as they don't have an error for it in the API as it's a new requirement, so they use the error they do have about requesting access to quickly.
Can be unblocked by buying something through your Product Advertisement link, but not sure how fast the unblocking is, if you have to wait for the next billing month or if it takes effect in a few days.