Um, hi

I think the problem is you haven't filled out the WEAPON_MATERIA_SLOTS for all your weapons.
In your database, you have 42 weapons, and 32 armors, but in the Materia System script, between lines 194 - 214:
CODE
WEAPON_MATERIA_SLOTS = {
1 => [1, 1], 2 => [1, 2], 3 => [2, 2], 4 => [4, 0],
5 => [1, 1], 6 => [1, 2], 7 => [2, 2], 8 => [4, 0],
9 => [1, 1], 10 => [1, 2], 11 => [2, 2], 12 => [4, 0],
13 => [1, 1], 14 => [1, 2], 15 => [2, 2], 16 => [4, 0],
17 => [1, 1], 18 => [1, 2], 19 => [2, 2], 20 => [4, 0],
21 => [1, 1], 22 => [1, 2], 23 => [2, 2], 24 => [4, 0],
25 => [1, 1], 26 => [1, 2], 27 => [2, 2], 28 => [4, 0],
29 => [1, 1], 30 => [1, 2], 31 => [2, 2], 32 => [4, 0]
}
# ~ Armors Materia Slots
ARMORS_MATERIA_SLOTS = {
1 => [1, 1], 2 => [1, 2], 3 => [2, 2], 4 => [4, 0],
5 => [1, 1], 6 => [1, 2], 7 => [2, 2], 8 => [4, 0],
9 => [1, 1], 10 => [1, 2], 11 => [2, 2], 12 => [4, 0],
13 => [1, 1], 14 => [1, 2], 15 => [2, 2], 16 => [4, 0],
17 => [1, 1], 18 => [1, 2], 19 => [2, 2], 20 => [4, 0],
21 => [1, 1], 22 => [1, 2], 23 => [2, 2], 24 => [4, 0],
25 => [1, 1], 26 => [1, 2], 27 => [2, 2], 28 => [4, 0],
29 => [1, 1], 30 => [1, 2], 31 => [2, 2], 32 => [4, 0]
}
You have all 32 armors defined, but for the weapons you only have 32 defined compared to your 42 in the database.
If you filled out the rest of the Materia's for the weapons to have the:
CODE
weapon_id => [paired_materia_id, single_materia_id]
e.g. 33 => [1, 1],
Then it should work again.
Oh, and um, the materia's are setup between lines 219 - 321, the first input to the Materia.new is the materia ID you need to put in the above code.