Some items are not accepted due to various reasons. This can be from market manipulation, which means that this item is being controlled by scammers causing the price to be inflated. Also it can be that this item has already been deposited many times into Howl, causing us to stopped accepting it due to us reaching the max capacity on said item.
Be sure to check back at any time to see if your item is no longer blacklisted as this can change frequently!