Open your 8.4 mapeditor and open your item.xml file (In your server folder). Press ctrl + f and search for the item name you want. Copy the ID of the item, now go to your mapeditor. Put your chest somewhere, right-click on it and paste the id in the unique id box. If that doesn't work, then I'm afraid you got some bugs in your server.
However, you should moveover to sql because of better security, stability and much easier though, when you've learnt everything. Also, you won't have any problems with the server like you're having now, using TFS.