UnrecognizedClientException

If you got a permission error while calling renderMediaOnLambda() or renderStillOnLambda():

UnrecognizedClientException: The AWS credentials provided were probably mixed up.

it means that the AWS credentials were correct, but don't allow access to a certain resource.

Most common cause: Calling a Remotion function inside a serverless function

When calling render inside an AWS Lambda function or a Vercel serverless function, that function already has it's own AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY environment variables set. However, these are from AWS itself and are different from the variables that Remotion uses to invoke serverless functions.

To avoid that conflict, you can change the name of the environment variables you set:

• Rename AWS_ACCESS_KEY_ID to REMOTION_AWS_ACCESS_KEY_ID
• Rename AWS_SECRET_ACCESS_KEY to REMOTION_AWS_SECRET_ACCESS_KEY

If both are set, Remotion will prefer the environment variables that are prefixed with REMOTION_, which should separate the two different credentials nicely.