imkSushi's Potion Addon Bug

Exception has been thrown by the target of an invocation.
  at System.Reflection.MonoCMethod.InternalInvoke (System.Object obj, System.Object[] parameters) [0x00000] in <filename unknown>:0
  at System.Activator.CreateInstance (System.Type type, Boolean nonPublic) [0x00000] in <filename unknown>:0
  at System.Activator.CreateInstance (System.Type type) [0x00000] in <filename unknown>:0
  at Terraria.ModLoader.Mod.AutoloadItem (System.Type type) [0x00000] in <filename unknown>:0
  at Terraria.ModLoader.Mod.Autoload () [0x00000] in <filename unknown>:0
  at Terraria.ModLoader.ModLoader.do_Load (System.Object threadContext) [0x00000] in <filename unknown>:0

Inner Exception:
Object reference not set to an instance of an object
  at imkSushisModPotionsAddon.Items.SkyUnrestPotion..ctor () [0x00000] in <filename unknown>:0
  at (wrapper managed-to-native) System.Reflection.MonoCMethod:InternalInvoke (System.Reflection.MonoCMethod,object,object[],System.Exception&)
  at System.Reflection.MonoCMethod.InternalInvoke (System.Object obj, System.Object[] parameters) [0x00000] in <filename unknown>:0