Adding Sprite to scenes causing EXC_BAD_ACCESS - ios

Question

So I couldn't find a good answer that works for my problem. I am creating a SpriteKit game on iOS. Im just going to give you guys a quick overview of my setup and then go over the problem. I think that's the best way to explain this.
The Setup:
Basically in my didMove(to view:) method I call two helper functions: setupNodes() and setupLevel(). What these functions do is load the different scenes and SKSpriteNodes into memory and then add them to the scene. Here is the code I use to do this:
func setupNodes(){
doubleVent = (loadForegroundOverlayTemplate("DoubleVent").copy() as! SKSpriteNode)
}
func loadForegroundOverlayTemplate(_ fileName: String) -> SKSpriteNode{
let overlayScene = SKScene(fileNamed: fileName)!
let overlayTemplate = overlayScene.childNode(withName: "ForegroundOverlay")!.copy() as! SKSpriteNode
return overlayTemplate
}
This now stores the scene which is a child of an SKNode called "ForegroundOverlay". I then pass this to a function called "createForegroundOverlay()" like so:
let overlaySprite = doubleVent
createForegroundOverlay(doubleVent)
and then "createForegroundOverlay" adds the SKSpriteNode stored in doubleVent to the scene like so:
func createForegroundOverlay(_ overlayTemplate: SKSpriteNode) {
let foregroundOverlay = overlayTemplate.copy() as? SKSpriteNode
lastOverlayPosition.x = lastOverlayPosition.x + (lastOverlayWidth + ((foregroundOverlay?.size.width)!)/2)
lastOverlayWidth = (foregroundOverlay?.size.width)!/2.0
foregroundOverlay?.position = lastOverlayPosition
//TESTING PURPOSES
if TESTING_NODE_POS{
print("The last overlay position x:\(lastOverlayPosition.x), y:\(lastOverlayPosition.y)")
print("The last overlay width is \(lastOverlayWidth)")
print("Adding a foreground overlay \(count)")
count += 1
}
//TESTING PURPOSES
if TESTING_BOX_OUTLINE {
let foregroundPos = foregroundOverlay?.position
let boxLocation = foregroundOverlay?.childNode(withName: "Box1")?.position
if boxLocation != nil {
print("The location of the box \(String(describing: boxLocation))")
print("The foregroundLocation is \(String(describing: foregroundPos))")
print("last overlay position is \(lastOverlayPosition)")
}
}
//add the foreground overlay as a child of the foreground node
fgNode.addChild(foregroundOverlay!)
}
the variables for positioning - lastOverlayPosition, lastOverlayWidth etc.. - are just properties of my GameScene class used to know where and when to add the overlay that was passed.
The fgNode is a node that I stored from my GameScene.sks file like so:
let worldNode = self.childNode(withName: "World")!
bgNode = worldNode.childNode(withName: "Background")!
bgCityNode = worldNode.childNode(withName: "BackgroundCity")
cityBGOverlayTemplate = (bgCityNode.childNode(withName: "Overlay")!.copy() as! SKNode)
cityOverlayWidth = bgCityNode.calculateAccumulatedFrame().width
backgroundOverlayTemplate = (bgNode.childNode(withName: "Overlay")!.copy() as! SKNode)
backgroundOverlayWidth = backgroundOverlayTemplate.calculateAccumulatedFrame().width
fgNode = worldNode.childNode(withName: "Foreground")!
This was also done in my setupNodes() method.
The problem:
So maybe some of you guys have already seen the problem, but the problem is that when I launch my game it crashes and I get the message:
"Thread 1: EXC_BAD_ACCESS: (code = 1, address = 0x78)"
It is the exact same message every single time a crash occurs. I think I understand what the error is saying. Basically there is a pointer pointing to some location in memory (0x78) that has nothing there. So dereferencing that pointer obviously causes a fault. Here is where I get confused... This only happens about 50% of the time. when I run and build the project it builds successfully every time and then crashes 50% of the time with that error message. Secondly, this occurs at the very beginning. This is odd to me because how can some memory already be freed resulting in a bad pointer at the very beginning of the game. Also if the crash doesn't occur at launch then a crash never occurs except for when I reload the scene after the game over scene is displayed, which is basically the same as the game being relaunched.
With some time I narrowed the problem to one line of code:
fgNode.addChild(foregroundOverlay!)
if I comment this line out, no crash ever occurs (I tried building and running 50 times). The problem must be with the foregroundOverlay variable, which was setup using the code in the setup section of this discussion. So I have no idea how to fix this... Any Ideas??
P.S. it might also be worth noting that adding a child to the scene in this way only noticeably became a problem when I upgraded to xCode 10.0 and that I have considered using zombies, but I don't think that would help since the crash only happens at the launch of the game.
If I was unclear anywhere please let me know.