The Power Core outerwear (unlocked by completing the Alternative Fuel achievement) appears on my character once I sign in, but once I select Dressing Room and Edit Character, the outfit piece becomes invisible. It is also invisible during gameplay regardless of how the dressing room character appears.

Steps to reproduce:

1. Use a dried kelp block to power a furnace (unlocks the Alternative Fuel achievement and the Power Core)
2. Apply the Power Core in the character editor