Mac App Crashing with Illegal Instructions

For some reason, people seem to think they need to make an entirely new thread to add a line of text or correct a spelling mistake...

You have ONE HOUR from posting something to edit it. If you're outside that window, and the edit is necessary - your edit above really wasn't necessary - just reply to your own post.

There is no reason to create duplicate posts within an hour. It just clutters up the forums.

After some digging I found out that SwiftData is causing the problem. More concrete relationships

I have a class Account with has (optional) categories

@Relationship(deleteRule: .cascade, inverse: \Category.account)
var _categories: [Category]?
var categories: [Category] {
    self._categories ?? []
}

in the class Category I have the a simple account variable

var account: Account

The application crahses when I use the following init function in Account (at the last line)

    init(id: Int,
         income: Bool,
         location: String,
         maintainance: Bool,
         special: Bool,
         taxRate: Float,
         tenant: String,
         title: String) {
        self.id = id
        self.income = income
        self.location = location
        self.maintainance = maintainance
        self.special = special
        self.taxRate = taxRate
        self.tenant = tenant
        self.title = title
self._categories = []
    }

or when I use those lines

        // category not found, so create one
        let category: Category = Category(title: categoryName, account: self)
        if self._categories == nil {
            self._categories = [category]
        }

Maybe the underscore in the property name is causing an issue, could you try with a different name? And shouldn't that property be private so you can only access the relationship in one way?