my Config: 

{
  "Backpack Size (1-3)": 3,
  "Blacklisted Items (Item Shortnames)": [
    "explosive.timed",
    "explosives",
    "ammo.rocket.hv",
    "ammo.rocket.fire",
	"ammo.rocket.basic",
    "ammo.rocket.basic",
    "sulfur",
    "sulfur.ore",
	"gunpowder",
    "charcoal",
    "weapon.mod.8x.scope",
    "autoturret",
	"grenade.beancan",
    "grenade.f1",
	"ammo.rifle.explosive",
    "explosive.satchel",
	"scrap",
    "surveycharge",
	"lmg.m249",
	"rifle.m39",
	"rifle.l96",
	"grenade.smoke"	
  ],
  "Drop On Death": false,
  "Erase On Death": false,
  "Hide On Back If Empty": false,
  "Show On Back": false,
  "Use Blacklist": true
}​

Merged post

Calling hook CanAcceptItem resulted in a conflict between the following plugins: Backpacks - CannotAccept (CanAcceptResult), Skins (True (Boolean))

Skins has been known to have a problem with other plugins with accepting items.
There's a fix somewhere that allows all of this, I just need to find it.