When a Blueprint is launched via Marketplace, it uses the credential that is configured in the Project Environment. If the credential is invalid, the Blueprint deployment will fail with a check login error. To fix this issue, the developer needs to verify and update the credential in the Project Environment and ensure that it has the required permissions to access the target infrastructure and applications. References: Nutanix Multicloud Automation Administration (NMCAA), page 29-30; [Nutanix Certified Professional - Multicloud Automation (NCP-MCA) Exam Blueprint Guide] (https://www.nutanix.com/content/dam/nutanix/resources/support/ncp-mca-ebg.pdf), section 3.1.