Here's the output of the debug error when it crashes: I'm also receiving the following failed assertion: wiftData/ModelContext.swift:3253: Fatal error: Failed to identify a store that can hold instances of SwiftData._KKMDBackingData<Presents_2024.Item> from [:] error: Assertion failed: (byte_size > 0 && byte_size <= 8 && "GetMaxU64 invalid byte_size!"), function GetMaxU64, file DataExtractor.cpp, line 527 Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it): 0 LLDB 0x0000000115319aac llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 56 1 LLDB 0x0000000114e7a198 lldb_private::lldb_assert(bool, char const*, char const*, char const*, unsigned int) + 148 2 LLDB 0x0000000114e73818 lldb_private::DataExtractor::GetMaxU64(unsigned long long*, unsigned long) const + 72 3 LLDB 0x0000000114d7ded0 lldb_private::CompilerType::GetValueAsScalar(lldb_private::DataExtractor const&, unsigned long long, unsigned long, lldb_private::Scalar&, lldb_private::ExecutionContextScope*) const + 304 4 LLDB 0x0000000114cb9b9c lldb_private::Value::ResolveValue(lldb_private::ExecutionContext*, lldb_private::Module*) + 388 5 LLDB 0x0000000114cbc93c lldb_private::ValueObject::ResolveValue(lldb_private::Scalar&) + 104 6 LLDB 0x0000000114cbf814 lldb_private::ValueObject::GetValueAsSigned(long long, bool*) + 140 7 LLDB 0x0000000114b4fba8 lldb::SBValue::GetValueAsSigned(long long) + 160 8 lldb-rpc-server 0x0000000100c5fe70 rpc_server::_ZN4lldb7SBValue16GetValueAsSignedEx::HandleRPCCall(rpc_common::Connection&, rpc_common::RPCStream&, rpc_common::RPCStream&) + 92 9 lldb-rpc-server 0x0000000100c6a2b8 rpc_common::Connection::PrivateHandleRPCPacket(rpc_common::RPCPacket&, rpc_common::RPCPacket&, bool&) + 628 10 lldb-rpc-server 0x0000000100c6de8c Packets::ProcessPackets() + 564 11 lldb-rpc-server 0x0000000100c6dbf4 Packets::ReadThread() + 276 12 lldb-rpc-server 0x0000000100c6dad4 Packets::RunReadThread(void*) + 12 13 libsystem_pthread.dylib 0x00000001904f72e4 _pthread_start + 136 14 libsystem_pthread.dylib 0x00000001904f20fc thread_start + 8 Please file a bug report against lldb reporting this failure log, and as many details as possibleerror: Assertion failed: (byte_size > 0 && byte_size <= 8 && "GetMaxU64 invalid byte_size!"), function GetMaxU64, file DataExtractor.cpp, line 527 Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it): 0 LLDB 0x0000000115319aac llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 56 1 LLDB 0x0000000114e7a198 lldb_private::lldb_assert(bool, char const*, char const*, char const*, unsigned int) + 148 2 LLDB 0x0000000114e73818 lldb_private::DataExtractor::GetMaxU64(unsigned long long*, unsigned long) const + 72 3 LLDB 0x0000000114d7ded0 lldb_private::CompilerType::GetValueAsScalar(lldb_private::DataExtractor const&, unsigned long long, unsigned long, lldb_private::Scalar&, lldb_private::ExecutionContextScope*) const + 304 4 LLDB 0x0000000114cb9b9c lldb_private::Value::ResolveValue(lldb_private::ExecutionContext*, lldb_private::Module*) + 388 5 LLDB 0x0000000114cbc93c lldb_private::ValueObject::ResolveValue(lldb_private::Scalar&) + 104 6 LLDB 0x0000000114cbf6ec lldb_private::ValueObject::GetValueAsUnsigned(unsigned long long, bool*) + 140 7 LLDB 0x0000000114b4fcc0 lldb::SBValue::GetValueAsUnsigned(unsigned long long) + 160 8 lldb-rpc-server 0x0000000100c5ff18 rpc_server::_ZN4lldb7SBValue18GetValueAsUnsignedEy::HandleRPCCall(rpc_common::Connection&, rpc_common::RPCStream&, rpc_common::RPCStream&) + 92 9 lldb-rpc-server 0x0000000100c6a2b8 rpc_common::Connection::PrivateHandleRPCPacket(rpc_common::RPCPacket&, rpc_common::RPCPacket&, bool&) + 628 10 lldb-rpc-server 0x0000000100c6de8c Packets::ProcessPackets() + 564 11 lldb-rpc-server 0x0000000100c6dbf4 Packets::ReadThread() + 276 12 lldb-rpc-server 0x0000000100c6dad4 Packets::RunReadThread(void*) + 12 13 libsystem_pthread.dylib 0x00000001904f72e4 _pthread_start + 136 14 libsystem_pthread.dylib 0x00000001904f20fc thread_start + 8 Please file a bug report against lldb reporting this failure log, and as many details as possible

Also getting these errors that might be related... 🤔 SwiftData/DefaultStore.swift:442: Fatal error: API Contract Violation: Editors must register their identifiers before invoking operations on this store SwiftData.DefaultStore: 68B5BA57-CC77-4EB2-AF60-60EE36D4B962 did not. error: the replacement path doesn't exist: "/var/folders/6z/x5z1g5jx7bz8sd27794j7bpw0000gn/T/swift-generated-sources/@__swiftmacro_13Presents_20248ItemListV5items33_26959148E02528011C522F13E1D6E443LL5QueryfMa_.swift" error: the replacement path doesn't exist: "/var/folders/6z/x5z1g5jx7bz8sd27794j7bpw0000gn/T/swift-generated-sources/@__swiftmacro_13Presents_20248ItemListV5items33_26959148E02528011C522F13E1D6E443LL5QueryfMa_.swift" Can't show file for stack frame : <DBGLLDBStackFrame: 0x16bdfce20> - stackNumber:15 - name:ItemList.items.getter. The file path does not exist on the file system: /var/folders/6z/x5z1g5jx7bz8sd27794j7bpw0000gn/T/swift-generated-sources/@__swiftmacro_13Presents_20248ItemListV5items33_26959148E02528011C522F13E1D6E443LL5QueryfMa_.swiftCan't show file for stack frame : <DBGLLDBStackFrame: 0x16bdfce20> - stackNumber:15 - name:ItemList.items.getter. The file path does not exist on the file system: /var/folders/6z/x5z1g5jx7bz8sd27794j7bpw0000gn/T/swift-generated-sources/@__swiftmacro_13Presents_20248ItemListV5items33_26959148E02528011C522F13E1D6E443LL5QueryfMa_.swift

Here's how I initialize the SwiftData store using DocumentGroup. Please let me know if I need to provide any future info. Bug logged as Feedback (FB15100795) // // Presents_2024App.swift // Presents 2024 // // Created by Benjamin Lee on 07/06/2024. // import RichTextKit import SwiftData import SwiftUI import UniformTypeIdentifiers @main struct Presents_2024App: App { // MARK: Properties #if os(iOS) @UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate #elseif os(macOS) @NSApplicationDelegateAdaptor(AppDelegate.self) var appDelegate #endif @Environment(\.modelContext) private var modelContext @FocusState private var isFocused: Bool @StateObject private var transientSettings = TransientSettings() // MARK: Computed Properties var body: some Scene { #if os(iOS) DocumentGroupLaunchScene("Present's 2024") { NewDocumentButton("New Activity...") } background: { Image(.background) .resizable() .scaledToFill() .ignoresSafeArea() } overlayAccessoryView: { _ in AccessoryView() } #endif DocumentGroup(editing: .presentsDocument, migrationPlan: Presents_2024MigrationPlan.self, editor: { RootView() .environmentObject(appDelegate) .environmentObject(transientSettings) .focused($isFocused) .onAppear { isFocused = true DispatchQueue.main.async { // Here, you might need to enforce the focus on the RootView #if os(macOS) if let window = NSApplication.shared.windows.first { window.makeFirstResponder(window.contentView) } #endif } } .onKeyPress(.leftArrow) { DispatchQueue.main.async { if transientSettings.selectedTab > 0 { transientSettings.selectedTab -= 1 } print("⬅️ pressed") } return .handled } .onKeyPress(.rightArrow) { DispatchQueue.main.async { if transientSettings.selectedTab < transientSettings.numberOfItems - 1 { transientSettings.selectedTab += 1 } print("➡️ pressed") } return .handled } }, prepareDocument: { context in // Prepare the document before it is opened or edited. // Insert example Bookend Item let newBookend = Bookend(firstLine: NSAttributedString(""), secondLine: NSAttributedString(""), thirdLine: NSAttributedString(""), bookendType: .welcome) let newItem = Item(itemText: "A Bookend Video", itemType: .bookend, order: 0) newItem.bookends.append(newBookend) context.insert(newItem) // Insert example Question Item let question = Question(questionText: NSAttributedString("An Example Question")) let item = Item(itemText: "An Example Question", itemType: .question, order: 1) item.questions.append(question) context.insert(item) context.insert(Brand.defaultBrand) }) // .commands { // SidebarCommands() // #if os(macOS) //// AboutCommand() // #endif // RichTextCommand.FormatMenu() // //// CommandMenu("RichTextKit") { //// DemoUrl.github.link //// DemoUrl.documentation.link //// } // } } } extension UTType { static var presentsDocument: UTType { UTType(exportedAs: "eu.makeitso.presentsdocument") } } struct Presents_2024MigrationPlan: SchemaMigrationPlan { static var schemas: [VersionedSchema.Type] = [Presents_2024VersionedSchema.self] static var stages: [MigrationStage] = [] } struct Presents_2024VersionedSchema: VersionedSchema { static var versionIdentifier = Schema.Version(1, 0, 0) static var models: [any PersistentModel.Type] = [Item.self, UserSettings.self, Brand.self] } #Preview(traits: .sampleData) { @Previewable @State var appDelete = AppDelegate() @Previewable @State var transientSettings = TransientSettings() RootView() .environmentObject(appDelete) .environmentObject(transientSettings) }