10x Interface/AddOns/SavedInstances/Core/Core.lua:3154: bad argument #1 to 'pairs' (table expected, got nil)
[string "=[C]"]: ?
[string "@Interface/AddOns/SavedInstances/Core/Core.lua"]:3154: in function Refresh' [string "@Interface/AddOns/SavedInstances/Core/Core.lua"]:2613: in function <Interface/AddOns/SavedInstances/Core/Core.lua:2613> [string "=[C]"]: ? [string "@Interface/AddOns/Quartz/libs/AceBucket-3.0-4/AceBucket-3.0.lua"]:69: in function <...e/AddOns/Quartz/libs/AceBucket-3.0/AceBucket-3.0.lua:67> [string "@Interface/AddOns/Quartz/libs/AceBucket-3.0-4/AceBucket-3.0.lua"]:85: in function func'
[string "@Interface/AddOns/BagSync/libs/AceTimer-3.0-17/AceTimer-3.0.lua"]:57: in function <...ce/AddOns/BagSync/libs/AceTimer-3.0/AceTimer-3.0.lua:50>

SI.WorldBosses is defined in other file and shouldn't be nil, so your install might be broken. Reinstall can solve this.