What determines whether a weapon can have mod slots added or not?

[Zxurian]

Is there something in the UI that I'm missing?
Some white weapons can have at least 3, yet some green only are allowed one.
Is there something anywhere that says what the criteria is?

[X Connorz X]

All weapons can have 4 mod slots, if a weapon doesn't have four you can add some onto it. To add mod slots un-equip the weapon from all of the classes that it is on, then go onto the salvage matrix and put the weapon into it. When the weapon is in the salvage matrix it should have an option to [add mod slots] click on that and it will add one slot after ten minutes of waiting. After that ten minutes you can add another and another.

[Mog]

Is there something in the UI that I'm missing?
Some white weapons can have at least 3, yet some green only are allowed one.
Is there something anywhere that says what the criteria is?

From some testing with various items it appears that some weapons cannot have more mods or mod slots added to them. So I guess it depends on the item. The weapons description doesn't clearly show this however or if it does then I just cannot tell by quickly looking at it.

[X Connorz X]

You have to have your weapon unequipped from ALL of the loadouts that it is on and it CAN'T ALREADY HAVE MODS ON IT. Then you put it into the salvage matrix and add slots to it.

[Betelgeuse]

So when choosing a weapon in Salvage Matrix that has a slot open, I would select the mod and it would bring up the window as blank.
Is this because I had it equipped?

Some of this stuff is kind of confusing

[Valethar]

You have to have your weapon unequipped from ALL of the classes that it is on

The word you're looking for here is 'loadout'.

[Dtrick]

From some testing with various items it appears that some weapons cannot have more mods or mod slots added to them. So I guess it depends on the item. The weapons description doesn't clearly show this however or if it does then I just cannot tell by quickly looking at it.

If you look under the gun icon you will see --0- or ----. This means that a weapon can have mod slots added to it. The 0 means that the slot is already open. So a weapon with all mod slots open would have 0000 under it. First slot is stock, second barrel, third clip and fourth is scope. So a weapon that is -00- has the barrel and clip mod slot open on it.

For weapons that can not have mods, there is nothing under the icon. Also, if you click modify weapon, it states that there are no actions for this weapon.

[Valethar]

So when choosing a weapon in Salvage Matrix that has a slot open, I would select the mod and it would bring up the window as blank.
Is this because I had it equipped?

Some of this stuff is kind of confusing

Probably, yes. Make sure to go into each of your loadouts, found above the picture on your character screen, and replace that weapon with something else. You cannot have it equipped in any loadout and do anything beyond adding a mod to an existing slot, and sometimes not even that.

Once you have it out of each of your loadouts, you can then put it into the matrix to have a slot added, destroy existing mods in slots, retrieve existing mods (destroys weapon) or salvage it.

Bear in mind that loadouts are currently bugged, and you will literally have to open each loadout, exit the screen back to the third person view, then re-open it in order to swap any item. In most cases, this means you would have to do this as many as 4 times to replace both weapons, the shield and your grenade, for example. It requires a little patience and can be ridiculously frustrating if you have the bug, but that method usually works.

[chaoswolf]

be careful when doing this i was add mod slots to an assault rife and then out of nop wear it just vanished. it could of just been a bug and yes i did report it in but just a heads up it could happen to you as well

[X Connorz X]

@Betelgeuse

I don't quite understand what you are saying so sorry if this doesn't resolve your problem.

When you are adding mods select the weapon that you want and then select [add mods]. When you are on this part select the 4 mods that you wish to add to your gun (make sure that the mods that you want to add are for your gun type). Then when you have successfully chosen the mods click on the bar at the bottom that says [Start Action]. That should add the mods to your gun but please tell me if this doesn't help.