[Closed] custom attributes ui & controller connection severed

Ive made custom attributes on a modifier that i will use to drive finger rotations in a rig. Im having a hard time understanding why the connection between the ui spinners and their controllers is severed if re-open the scene?

for o in selection do 
	(
	try if o.modifiers[1].name == "Fingers" do deletemodifier o 1 catch()
	b = emptymodifier()
	b.name = "Fingers"
	try addmodifier o b catch()
	fing = attributes fingers
		(
		parameters main rollout:fingers_ro
			(
			ff type:#float ui:ffi default:0.0 animatable:true 
			bf type:#float ui:bfi default:0.0 animatable:true 
			lf type:#float ui:lfi default:0.0 animatable:true
			rf type:#float ui:rfi default:0.0 animatable:true
			)
		rollout fingers_ro "Finger rotations" width:161 height:50
			(
			spinner ffi	"Front" range:[-1.5,1.5,0.05] scale:0.01 
			spinner bfi	"Back"  range:[-1.5,1.5,0.05] scale:0.01 
			spinner lfi	"Left"  range:[-1.5,1.5,0.05] scale:0.01 
			spinner rfi	"Right"  range:[-1.5,1.5,0.05] scale:0.01 
			)
		)
	custattributes.add o.modifiers["Fingers"] fing
	for j = 1 to 4 do o.modifiers["Fingers"].fingers[j].controller = bezier_float()
	puoli ="L"
	if (findstring o.name"_L") != undefined then puoli = "L" else puoli = "R"
	fingerz = #("F","B","L","R")
	for j in fingerz do 
		(
		kont = Float_expression()
		kont.AddScalarTarget "daa" (execute("$.modifiers[1].fingers."+j+"f.controller"))
		kont.Setexpression "daa"
		kont2 = Float_expression()
		kont2.AddScalarTarget "daa" (execute("$.modifiers[1].fingers."+j+"f.controller"))
		kont2.Setexpression "-daa"
		execute("$kurki_RIG_leg_"+puoli+"_fingerbone_"+j+"_01.rotation.controller[1][2].controller = kont")
		execute("$kurki_RIG_leg_"+puoli+"_fingerbone_"+j+"_02.rotation.controller[1][3].controller = kont2") 
		)
	)