I'd try putting them in both in 'Objects' and 'My Objects', also try putting the image (.png/.jpg) files into the 'Textures' then replacing them if asked in an option box that may pop up. Also make sure that you put in the right name of the Material file in the 'Material' box shown here:
(http://i39BannedImageSite/5ovwwo.png)
If you don't know the material for it, open up the .cfg file in note pad for your object that will be found in Feral Heart >> Media >> Objects >> My Objects. You will then find the material file for your object then all you need to do is type it in correctly in the Material box in your Object maker.
Looking forward to seeing future news ^^ I hope everything turns out well for you, enjoy your map making! c: