Why won't attribute modifiers add up on my armor?

Question

I am trying to make a new set of armor called the Fullerite armor. It has its own custom resource but it is made of gold. I'm trying to modify the gold to have more protection than diamond. It also is going to give you more health. This is the command I am using:

Helmet:

/give @p golden_helmet 1 1 {display:{Name:"Fullerite Helmet"},AttributeModifiers:[{AttributeName:"generic.maxHealth",Name:"generic.maxHealth",Amount:2,Operation:0,UUIDMost:61127,UUIDLeast:23056},{AttributeName:"generic.armor",Name:"generic.armor",Amount:3,Operation:1,UUIDMost:88181,UUIDLeast:199509},{AttributeName:"generic.armorToughness",Name:"generic.armorToughness",Amount:2,Operation:1,UUIDMost:17664,UUIDLeast:119384}],Unbreakable:1,ench:[{id:0,lvl:4}],HideFlags:2}

Chestplate:

/give @p golden_chestplate 1 1 {display:{Name:"Fullerite Chestplate"},AttributeModifiers:[{AttributeName:"generic.maxHealth",Name:"generic.maxHealth",Amount:2,Operation:0,UUIDMost:61127,UUIDLeast:23056},{AttributeName:"generic.armor",Name:"generic.armor",Amount:8,Operation:1,UUIDMost:88181,UUIDLeast:199509},{AttributeName:"generic.armorToughness",Name:"generic.armorToughness",Amount:2,Operation:1,UUIDMost:17664,UUIDLeast:119384}],Unbreakable:1,ench:[{id:0,lvl:4}],HideFlags:2}

Leggings:

/give @p golden_leggings 1 1 {display:{Name:"Fullerite Leggings"},AttributeModifiers:[{AttributeName:"generic.maxHealth",Name:"generic.maxHealth",Amount:2,Operation:0,UUIDMost:61127,UUIDLeast:23056},{AttributeName:"generic.armor",Name:"generic.armor",Amount:6,Operation:0,UUIDMost:88181,UUIDLeast:199509},{AttributeName:"generic.armorToughness",Name:"generic.armorToughness",Amount:2,Operation:0,UUIDMost:17664,UUIDLeast:119384}],Unbreakable:1,ench:[{id:0,lvl:4}],HideFlags:2}

Boots:

/give @p golden_boots 1 1 {display:{Name:"Fullerite Boots"},AttributeModifiers:[{AttributeName:"generic.maxHealth",Name:"generic.maxHealth",Amount:2,Operation:0,UUIDMost:61127,UUIDLeast:23056},{AttributeName:"generic.armor",Name:"generic.armor",Amount:3,Operation:0,UUIDMost:88181,UUIDLeast:199509},{AttributeName:"generic.armorToughness",Name:"generic.armorToughness",Amount:2,Operation:0,UUIDMost:17664,UUIDLeast:119384}],Unbreakable:1,ench:[{id:0,lvl:4}],HideFlags:2}

When I put this on, it works just fine, but when I put another piece of armor on it doesn't add any armor points or it replaces the armor points it already had. Same for the extra health. I am playing in 1.9.2. Anyone know why they won't add up and they only work when worn separately?

Answer 1

The UUIDLeast/UUIDMost tags must contains values that are "universally unique". The modifiers are overwriting one another dependent on the UUID.

You must change the values to be unique across all items. Example of a set of valid UUIDs that can be applied to the player:

{UUIDLeast:1,UUIDMost:1}
{UUIDLeast:1,UUIDMost:2}
{UUIDLeast:2,UUIDMost:1}
{UUIDLeast:2,UUIDMost:2}