This script throws an exception: key TheAnyKey; default { state_entry() { TheAnyKey = NULL_KEY; llOwnerSay("Hello world!"); } } System.InvalidProgramException: Invalid IL code in LSL_2d835e04_fee6_b208_4a1e_e1549c71e776:defaultstate_entry (): IL_004a: stfld 0x04000001 at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (object,object[]) at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] This does not occur when assigning the value in a declare, or when assigning the value of a function or another variable. That is, this will run with no problem: default { state_entry() { key TheAnyKey = NULL_KEY; key TheOtherKey = "34ffd167-9c28-4fb0-8f19-8b86294abf95"; TheAnyKey = llGetOwner(); TheAnyKey = TheOtherKey; llOwnerSay("Hello world!"); } }