So yesterday I got a ton of errors which Mike put me on the right track onto saying it was probably an add-on. Those errors started on the 18th of november but luckily (though i would have eventually found the add-on) I got a pc from <author> on the 18th so it was easy to track down the add-on causing the errors.
So the suggestion is whenever you install an add-on or upgrade in the listings it displays the time and date installed. This will help track down if server errors are created and logged making it easier for the novice to track down. Bad Idea? It wasn't fully thought out and it did pop into my head so rashly suggesting it.
Not even sure this is something that is maybe done by xenforo or the 3rd party add-on devs.