@AEMnewbie,
You need to be extra careful when it comes to managing JCR nodes from a live environment. If asset versioning is corrupted, then the only next best way is to go into the AEM publish and download the original Asset file... next re-upload the same Asset into the author, and this should kick off a workflow to rebuild all the renditions for that given Asset. If uploading a new Asset does not meet your needs, you can go into the AEM publish env, and create a new content package in package manager; download it. Next, from the AEM author env, disable AEM workflow launchers, upload & install the content package into AEM author, and finally re-enable AEM workflow launchers; managing the life cycle of AEM workflow launchers will ensure that during your installation of the AEM DAM Asset, your workflow launchers will not be applied to the Asset that is being installed into the AEM author.
