Took me a while to figure out what to do but I think this is what you're after.
System.NullReferenceException: Object reference not set to an instance of an object.
at PoroCYon.ICM.Controls.ModFilter`1..ctor(ModBase base) in c:\Users\x\Documents\My Games\Terraria\tAPI\Mods\Sources\Ingame Cheat Menu\Ingame Cheat Menu\Controls\ModFilter.cs:line 52
at PoroCYon.ICM.Controls.NpcFilter..ctor(ModBase base) in c:\Users\x\Documents\My Games\Terraria\tAPI\Mods\Sources\Ingame Cheat Menu\Ingame Cheat Menu\Controls\ModFilter.cs:line 206
at PoroCYon.ICM.Menus.NpcUI.Init() in c:\Users\x\Documents\My Games\Terraria\tAPI\Mods\Sources\Ingame Cheat Menu\Ingame Cheat Menu\Menus\NpcUI.cs:line 110
at PoroCYon.MCT.UI.MctUI.AddCustomUI(CustomUI customUI) in C:\Users\x\Dropbox\PoroCYon.MCT\Mod Creation Tools\UI\MctUI.cs:line 202
at PoroCYon.ICM.IcmMod.OnAllModsLoaded() in c:\Users\x\Documents\My Games\Terraria\tAPI\Mods\Sources\Ingame Cheat Menu\Ingame Cheat Menu\IcmMod.cs:line 87
at TAPI.Hooks.Call(Action[] ts)
at TAPI.Mods.Load()
(privacy thing again)
at PoroCYon.ICM.Controls.ModFilter`1..ctor(ModBase base) in c:\Users\x\Documents\My Games\Terraria\tAPI\Mods\Sources\Ingame Cheat Menu\Ingame Cheat Menu\Controls\ModFilter.cs:line 52
at PoroCYon.ICM.Controls.NpcFilter..ctor(ModBase base) in c:\Users\x\Documents\My Games\Terraria\tAPI\Mods\Sources\Ingame Cheat Menu\Ingame Cheat Menu\Controls\ModFilter.cs:line 206
at PoroCYon.ICM.Menus.NpcUI.Init() in c:\Users\x\Documents\My Games\Terraria\tAPI\Mods\Sources\Ingame Cheat Menu\Ingame Cheat Menu\Menus\NpcUI.cs:line 110
at PoroCYon.MCT.UI.MctUI.AddCustomUI(CustomUI customUI) in C:\Users\x\Dropbox\PoroCYon.MCT\Mod Creation Tools\UI\MctUI.cs:line 202
at PoroCYon.ICM.IcmMod.OnAllModsLoaded() in c:\Users\x\Documents\My Games\Terraria\tAPI\Mods\Sources\Ingame Cheat Menu\Ingame Cheat Menu\IcmMod.cs:line 87
at TAPI.Hooks.Call(Action[] ts)
at TAPI.Mods.Load()
(privacy thing again)