Once you start to craft large amounts of items, your inventory will invitably fill up. That is in and of itself not a tragedy, though certainly annoying. As it turns out, some players have had to face a much more drastic problem: Their items simply vanished. Having counted the items before, they were sure that they had everything in their inventory when they started. But it wasn’t there anymore!
Now, it is not impossible to misplace something once in a while, and yet, the more often this happens in-game the more suspicious one gets. Are there thieves at work? One wouldn’t have put it past the developers to add the elves from the Shoemakers Tale into the game. Unfortunately though, the end-products were missing too.
This prompted a reddit user to investigate, and his findings are truly enlightening (and should certainly put some minds at ease):
The inventory has a hidden limit of 146 slots. If you use put any more than that into it, it will delete those items!
So keep that in mind or you risk losing the items you have worked so hard for. So far there hasn’t been a comment from the developers on the matter, however the general consent is that this, in its current form, is a bug and not a feature.