Same problem with me as well. Neither alignment, nor .timer works.

I dont have an answer and don't know how to generate 5.5" screenshots. However, Apple clarified that those are needed :( https://developer.apple.com/forums/thread/719822

My model do not have any @Attribute(.unique) All properties have default values Relationships are marked as optional App is using CloudKit for iCloud syncronization A brandnew app with the same model does not have this issue. When I uncheck "CloutKit" in Signing & Capabilities, the app launch normally.

Widget can obtain the data without error/crash from modelContainer using this code: guard let modelContainer = try? ModelContainer(for: MyTodo.self) else { return [] }

I have now identified that this issue is happening due to Relationships in my model. My MyToDo has task defined like this: @Relationship(deleteRule: .cascade) var tasks: [MyTask]? = [] and MyTask has reference back as following: var todo: MyTodo? Both of them are optional as required for CloudKit. This model can be read in iOS 17.3, but in 17.4 beta, it crashes!

It seems for whatever reason inverse relationship needs to be explicitly defined. Change from this: @Relationship(deleteRule: .cascade) var tasks: [MyTask]? = [] to @Relationship(deleteRule: .cascade, inverse: \MyTask.todo) var tasks: [MyTask]? = [] has solved the crash issue. Works both in iOS 17.3 and 17.4.