??? problems with a quest ... gui ... and lighting stuff

ok so when ever i try to make a quest that when finished unlocks a screen gui it never works ... so my question is ... is it possible? cause for my game i want you to be able to get a new gui for Mystique after you complete a certain quest . i know this may be a little confusing to follow but if you can help me get this to work it would be amazing ...

would it be easier to do if i kept my heroes in "Lighting"? if so dose anyone have a script that i can used to access my 2.0 morphs from lighting cause my 3.0 one doesn't work on 2.0.

~Fin