When doing the initial validate(), skip validating values by setting the stack strict_validate to False, otherwise we incorrectly fail validation when values are passed in via properties/parameters which refer to resources in the parent stack. Co-Authored-by: Angus Salkeld <asalkeld@mirantis.com> Change-Id: Ib75c2de6c32373de72901b9f7c5e3828bd9ee7d9 Closes-Bug: #1407100 Closes-Bug: #1407877 Closes-Bug: #1405446