We're experiencing connectivity issues from AWS to some parts of the outer world (aka the Internet). As our transformation sandbox server (ovh-tapi.keboola.com) is not in AWS you may experience failures when creating sandboxes and credentials. If this is not resolved within AWS shortly, we'll be switching the sandbox server into AWS network.
We will keep this post updated with the current status.
UPDATE (2:00pm PST): Connectivity seems to work fine now.