My level will not load...

[HakePT]

EDIT : it says (16,1) : unexpected token

Like it says go to line 16, 1st character:
{ <--
AddUseItemCallback("", "StudyKey", "castle_arched01_3", "UsedKeyOnDoor", true);

}<--

you don't place this here place it on void OnStart()
{
*(what else you have let it stay there as well)*
AddUseItemCallback("", "StudyKey", "castle_arched01_3", "UsedKeyOnDoor", true);
}

Edit:
Remove the {} marked with <-- after you change the callback to OnStart.