swift

Force unwrap of nil Optional value

unexpectedly found nil while (unwrapping|implicitly unwrapping) an Optional

Fixes

1.Use optional binding: if let value = optional { ... }
2.Use guard let for early exit: guard let value = optional else { return }
3.Provide a default with nil coalescing: optional ?? defaultValue

optionalnilcrash

Related Errors

SwiftUI preview crash

SwiftUI.*Previews.*crashed.*The preview process was terminated

•Clean build folder: Cmd+Shift+K, then rebuild
•Check for force-unwrapped optionals or fatalError in preview code

Swift Combine publisher cancelled unexpectedly

Swift.*Combine.*Cancelled.*sink received completion.*failure

•Store the AnyCancellable in a Set to prevent premature deallocation
•Use .store(in: &cancellables) to retain the subscription

Core Data model incompatible with persistent store

CoreData.*NSInternalInconsistencyException.*model.*incompatible.*store

•Add a migration mapping model for schema changes
•Use lightweight migration: addPersistentStore with NSMigratePersistentStoresAutomaticallyOption