Yes, that's a common error! It happens when the workflow is trying to reference API credentials but can't find a valid credential ID (which needs to be in UUID format like "123e4567-e89b-12d3-a456-426614174000"). This usually occurs when: You've deleted or changed credentials that the workflow was using The credential wasn't properly saved when you set it up Are you using a tool that requires authentication (like an API key or OAuth)?