Also getting this error in Xcode RC 16. It seems happen whenever I call save after a delete.
modelContext.delete(transaction)
try? modelContext.save()
It does not seem to matter if the delete comes from within a component or from a ForEach.onDelete it yields the same error.
SwiftData/BackingData.swift:251: Fatal error: Context is missing for Optional(SwiftData.PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(url: x-coredata://13C3453D-78A0-423B-841D-FF28F6EB2B24/Transaction/p998), implementation: SwiftData.PersistentIdentifierImplementation))