One more piece of info - I just tried this with a local instance with a small portion of our site on it. The same behavior happened, but it was able to finish and finally display a preview after a half hour. I hoped that once this occurred, the process wouldn't need to repeat. But the next time I hi...

No errors are appearing, no traversal queries. Just a million edits suddenly as it seems to run through the whole system creating versions before doing the preview. And this is on AEM 6.4.0. Really baffled what's going on - does a preview always require the whole system to have a current version or ...

Huge apologies - I never got the notification you had responded! Will keep an eye on this thread now as this issue is still going on. Also... no idea why my username is suddenly different. That's fun