Adding items to NSArrayController causes EXC_BAD_INSTRUCTION - swift

Question

I've had the same problem for a few days now and it's been killing me. Whenever I run my script, I get a EXC_BAD_INSTRUCTION. It happens when I add an array of objects to an NSArrayController, bount to an NSTableView. Below is my code:
AppDelegate.swift:
import Cocoa
#NSApplicationMain
class AppDelegate: NSObject, NSApplicationDelegate {
#IBOutlet weak var window: NSWindow!
#IBOutlet weak var mainTabView: NSTabView!
#IBOutlet weak var tracksAC: NSArrayController!
#IBOutlet weak var albumsAC: NSArrayController!
func checkIfFileExists(atPath path: String, isDirectory: Bool = false, createIfNeeded createNew: Bool = false) -> Int {
var isDir: ObjCBool = ObjCBool(isDirectory)
if !FileManager.default.fileExists(atPath: path, isDirectory: &isDir) {
if createNew {
do {
if isDirectory {
try FileManager.default.createDirectory(atPath: path, withIntermediateDirectories: true)
}else{
FileManager.default.createFile(atPath: path, contents: nil)
}
return 2
}catch{
return 3
}
}else{
return 0
}
}
return 1
}
func applicationDidFinishLaunching(_ aNotification: Notification) {
//Create application support folder if it's not existent and populate with all needed files
let paths = NSSearchPathForDirectoriesInDomains(.applicationSupportDirectory, .userDomainMask, true)
let appSupportDir = paths[0] + "/Project Alpha"
//Create application folder if needed
let folderStatus = checkIfFileExists(atPath: appSupportDir, isDirectory: true, createIfNeeded: true)
if folderStatus == 1 || folderStatus == 2 {
_ = checkIfFileExists(atPath: appSupportDir + "/Songs.txt", createIfNeeded: true)
_ = checkIfFileExists(atPath: appSupportDir + "/Albums.txt", createIfNeeded: true)
_ = checkIfFileExists(atPath: appSupportDir + "/Genres.txt", createIfNeeded: true)
}
//Populate tracks table view
let tracks = getTracks()
print(tracks[0].name)
tracksAC.add(contentsOf: tracks) //This is where the error occures every time
}
func applicationWillTerminate(_ aNotification: Notification) {
// Insert code here to tear down your application
}
#IBAction func openAlbumsTab(_ sender: NSToolbarItem) {
mainTabView.selectTabViewItem(at: 1)
}
}
Classes.swift:
import Cocoa
class Track: NSObject {
func getLine() -> String? {
let songsFilePath = NSSearchPathForDirectoriesInDomains(.applicationSupportDirectory, .userDomainMask, true)[0] + "/Project Alpha/Songs.txt"
do {
let content = try String(contentsOfFile: songsFilePath)
let lines = content.components(separatedBy: "---===---")
let line = lines.first(where: {$0.hasPrefix(String(self.identifier) + ";")})
return line
}catch{
return nil
}
}
var identifier: Int
var name: String
var artist: String
var album: String
var genre: String
var vocals: String
var trackNumber: Int
init(line: String) {
let items = line.components(separatedBy: ";")
print(items)
self.identifier = Int(items[0])!
self.name = String(items[1])
self.artist = String(items[2])
self.genre = String(items[3])
self.vocals = String(items[4])
self.album = String(items[5])
self.trackNumber = Int(items[6])!
}
}
I have checked the getTracks function and normally it does return a list of Track objects, so I really don't know what's causing the error. The columns are bound to the array controller as shown via the link below:
screenshot
Any help would be greatly appreciated. Thanks in advance.