@Bryanvh No problem The issue you encountered wasn't very clear. Therefore, I've proposed a change to the XAPI to make the error more explicit (this will likely be implemented in future XAPI releases). So instead of SSL Certification failure the message will be: POOL_JOINING_MASTER_CERTIFICATE_NOT_IN_POOL_BUNDLE. Thank you very much for your patience and for bringing this issue to our attention. References: https://github.com/xapi-project/xen-api/pull/7112 LucienLassalle opened this pull request in xapi-project/xen-api closed xapi: Improve error reporting when pool join fails on TLS verification #7112