To delete a version:
Select Manage for your version.
Select the Manage Version drop-down list followed by Delete Version.
The Delete Version option will only be available to the version author or account owner if the version is unpublished.
You will be required to double confirm if you wish to delete the version. If an version is deleted, the interactivity, resources and design for that version will be lost. If you would like to use the design elsewhere for a new version, duplicate it before deleting it.
Be sure when deleting an version as it cannot be recovered.