What does this mean?

[_Babble_]

I have a DoL vest that I made and attached 2 materia onto. One materia was for GP, the other had +3 perception. But when I equip the item, I get the message "materia and aetherial attributes could not be restored." Also, in my gear set list, there is a warning sign. When I mouse over, it reads "one or more items were not melded with the specified materia."

What did I do wrong?

[bounddreamer]

Everything is fine. Update your gear set. It's basically telling you it can't equip you with a gear set that doesn't have materia, which is what you have saved under that set.

[_Babble_]

Ah, thank you so much! I hadn't noticed that it was no longer saved.

[Niwashi]

Any changes to materia, glamour, or even dye color will result in a warning message like that, saying that the gear saved in the set and the gear you currently have available to equip don't quite match. Just re-save the set after any such change to tell the system it's a change you want.