Why doesn't my script detect BoolValue's change?

Hello! I have made a Script, which detects if a BoolValue has changed and then checks if it's ticked. Though it does not work, obviously... The BoolValue does get ticked and unticked, but is not detected by this script.

Knife  = script.Parent
KnifeZone = game.ReplicatedStorage.KnifeZone
SwingCheck = Knife.Swinging

if SwingCheck.Value:Changed() then
    print("BoolValue changed!")
    if SwingCheck.Value == true then
        KZclone = KnifeZone:Clone()
        KZclone.Parent = game.Workspace
        KZclone.Position = Knife.Knife.Position
        KZclone.Orientation = Knife.Knife.Orientation
        wait(0.5)
        KZclone:Destroy()
    end
end

You’re attempting to reference a method of Value which doesn’t exist. Although there is a method of Instance that does listen for change events, it’s not titled Changed(), but in fact, GetPropertyChangedSignal(). Another similar signal is also the .Changed() event; although applicable in this situation, it only can listen for Values, whereas the separate method can fire for all modified properties—therefore recognized as a stronger practice.

SwingCheck:GetPropertyChangedSignal("Value"):Connect(function()
    print("Value Changed!")
    if SwingCheck then
        --// code Lines 8-13
    end
end)

Hey, LordTechet. What you are currently doing is trying to use an Event, as a Function.

.Changed cannot be used like you would use something like :Destroy().

It is a special event, also known as RBXScriptSignal.

They function by being combined with 2 different functions, .Changed:Wait(), or Changed:Connect(function).

In this case what you want to do is this:

Change this to an event.

if SwingCheck.Value:Changed() then

Like so:

SwingCheck.Value.Changed:Connect(function()
	--code
end)

Your finished code should look something similar to:

Knife  = script.Parent
KnifeZone = game.ReplicatedStorage.KnifeZone
SwingCheck = Knife.Swinging

SwingCheck.Value.Changed:Connect(function()
    print("BoolValue changed!")
    if SwingCheck.Value == true then
        KZclone = KnifeZone:Clone()
        KZclone.Parent = game.Workspace
        KZclone.Position = Knife.Knife.Position
        KZclone.Orientation = Knife.Knife.Orientation
        wait(0.5)
        KZclone:Destroy()
    end
end)

Is the boolvalue being changed by a localscript? If so, the server won't recognize a change in it. To get around this have the local script fire a remoteevent to change the value.