If you fail to create a resource stack, the following may be the reason.
The stack names created by the same user cannot be duplicate.
The stack name cannot contain non-alphanumeric characters, and cannot start with a digit.
Resource creation failure may result in a failure to create the resource stack. For example, if it fails to create an ECS instance in a region successfully, the resource stack creation in the same region also fails.
ROS limits that each user can create up to 50 stacks. If you have reached the top limit, you cannot create a new stack. See Limits.