Happens on server and single player.

As reported here w/ logs and minimum test setup:
MattiDragon/ExtendedDrawers#70

and here:
tom5454/Toms-Storage#257

This crash shouldn't happen anymore, as of Mythic Metals Decorations 0.6.0+ this use of the FAPI Transfer API no longer exists, and can therefore not return null.
Feel free to open a new issue should this still be the case