Error map
Could not cast value of type Swift: Could not cast value of type 'X' to 'Y'
iOS · layer 1, On your device
Centre: this error. First ring: errors it is linked with (12). Outer ring: what those are linked with. Colours show the layer of a request each error belongs to. Click any dot to re-centre the map on it; hover to follow its connections. The centre dot opens the error page.
Directly related (12)
Thread 1: signal SIGABRT (app crashes with "libc++abi: terminating")
The app deliberately aborted — an uncaught exception, failed assertion or fatalError. The console above the crash has the real me…
System.InvalidCastException: Unable to cast object of type 'X' to type 'Y'
An explicit cast failed because the object’s runtime type isn’t the target type.
The application was unable to start correctly (0xc0000142)
A DLL the program loads failed to initialise — often after an update, with corrupt runtimes, or when a desktop heap/session limit…
C/C++: free(): double free detected / double free or corruption (out) — Aborted (core dumped)
Memory was freed twice or the heap was corrupted (buffer overflow, freeing a non-heap pointer), so glibc aborted the program.
Illegal instruction (core dumped) (SIGILL)
The program used a CPU instruction your processor doesn’t support — typically AVX/AVX2 in prebuilt binaries (TensorFlow, MongoDB…
dyld: Library not loaded: @rpath/X.framework/X — Reason: image not found (crash on launch)
A dynamic framework the app needs at runtime isn’t embedded in the app bundle, so it crashes at launch.
C++: terminate called after throwing an instance of 'std::out_of_range' — what(): vector::_M_range_check
A C++ exception wasn’t caught anywhere, so std::terminate aborted the program. what() tells you the reason.
Swift: The compiler is unable to type-check this expression in reasonable time; try breaking up the expression into distinct sub-expressions
A long expression (often in a SwiftUI body) has too many possible type combinations for the compiler — or hides a type error.
Swift: Cannot convert value of type 'X' to expected argument type 'Y'
The value’s type doesn’t match what the function or property expects.
unable to dequeue a cell with identifier Cell - must register a nib or a class for the identifier or connect a prototype cell in a storyboard
The table/collection view was asked for a reusable cell identifier that was never registered.
Swift: 'X' is only available in iOS 16.0 or newer
You used an API that requires a newer iOS than your deployment target.
Swift: Type of expression is ambiguous without a type annotation (more context)
The compiler can’t infer which type you mean — often because of a typo or a wrong argument elsewhere in the expression.
Two steps away (36)
Fatal error: Unexpectedly found nil while unwrapping an Optional value
Swift force-unwrapped (`!`) an optional that was nil, crashing the app.
java.lang.IllegalArgumentException
A method rejected an argument value as invalid.
java.lang.ArithmeticException: / by zero
Integer division or modulo by zero.
AttributeError: 'X' object has no attribute 'y'
You accessed an attribute or method that doesn’t exist on that object type.
java.lang.ClassCastException: class A cannot be cast to class B
An object was cast to a type it isn’t.
java.lang.IllegalStateException
A method was called when the object wasn’t in the right state for it.
The application was unable to start correctly (0xc000007b)
A program loaded a DLL of the wrong architecture (32-bit vs 64-bit) or a corrupted runtime library.
VCRUNTIME140.dll was not found / MSVCP140.dll is missing
The program needs the Microsoft Visual C++ 2015–2022 Redistributable, which isn’t installed (or is damaged).
Segmentation fault (core dumped)
A program accessed memory it wasn’t allowed to, and the kernel killed it with SIGSEGV (exit code 139).
Kubernetes: OOMKilled (exit code 137)
The container used more memory than its limit, and the kernel killed it.
java.lang.OutOfMemoryError: Java heap space
The JVM ran out of heap memory and garbage collection couldn’t free enough.
Blue Screen: MEMORY_MANAGEMENT (Stop code 0x0000001A)
Windows detected a severe memory-management error — commonly faulty RAM, unstable memory settings or a bad driver.
exec /usr/local/bin/docker-entrypoint.sh: exec format error
The container tried to run a binary built for a different CPU architecture (arm64 vs amd64) — or a script with a broken shebang /…
FATAL: the database system is in recovery mode
PostgreSQL crashed (often OOM-killed) and is replaying WAL to recover.
no matching manifest for linux/arm64/v8 in the manifest list entries
The image has no build for your CPU architecture — typically pulling an amd64-only image on an Apple Silicon Mac or ARM server.
error while loading shared libraries: libX.so.N: cannot open shared object file: No such file or directory
The program needs a shared library (.so) that isn’t installed or isn’t on the loader’s search path.
.NET: Stack overflow. / Process is terminated due to StackOverflowException
Infinite or very deep recursion exhausted the thread’s stack; .NET can’t catch it and terminates the process.
Thread 1: EXC_BAD_ACCESS (code=1, address=0x0)
The app accessed memory it shouldn’t — a dangling pointer, released object, unsafe pointer misuse, a data race, or infinite recur…
java.util.NoSuchElementException: No value present
Code asked for an element that doesn’t exist — Optional.get() on empty, iterator.next() past the end, Scanner with no input.
Fatal error: Uncaught Exception: message in file.php:12
An exception was thrown and nothing caught it, so PHP stopped the script.
The application was unable to start correctly (0xc0000005) / Exception code 0xc0000005 access violation
A program tried to read or write memory it doesn’t own and Windows stopped it — buggy software, bad drivers/plugins, security sof…
error CS0246: The type or namespace name 'X' could not be found (are you missing a using directive or an assembly reference?)
The compiler doesn’t know the type — missing using, missing NuGet package/project reference, or a target framework mismatch.
error CS0103: The name 'x' does not exist in the current context
The identifier isn’t declared in scope — typo, variable declared in another block, missing using static, or a Razor/partial class…
error CS1061: 'X' does not contain a definition for 'Y' and no accessible extension method 'Y' accepting a first argument of type 'X' could be found
The member you call doesn’t exist on that type — typo, wrong type, missing using for an extension method, or an API removed in a…
TS7016: Could not find a declaration file for module 'x'. 'x.js' implicitly has an 'any' type.
The JavaScript package has no TypeScript types bundled and no @types package installed.
TS2304: Cannot find name 'x'.
TypeScript doesn’t know an identifier — a missing import, missing type definitions (e.g. for Node or Jest globals), or a typo.
TS2339: Property 'x' does not exist on type 'Y'.
TypeScript’s type for the object doesn’t include that property.
App Transport Security has blocked a cleartext HTTP resource load
iOS blocked an `http://` request (or a weak-TLS HTTPS one) because App Transport Security requires secure connections.
NSUnknownKeyException: this class is not key value coding-compliant for the key x
A storyboard/XIB has a connection to an outlet or action that no longer exists in the class (renamed or deleted), or the view’s c…
Main Thread Checker: UI API called on a background thread: -[UIView setNeedsLayout]
UIKit was used from a background thread; UI must only be touched on the main thread.
Swift: Fatal error: Index out of range
Code accessed an array index that doesn’t exist — empty arrays, off-by-one loops, or data changing while a table reloads.
Swift: No such module 'X' (module not found)
Xcode can’t find a Swift package, pod or framework you import.
Swift: Escaping closure captures mutating 'self' parameter
A mutating method of a struct tries to capture self in an escaping closure, which Swift forbids.
warning CS8618: Non-nullable property 'X' must contain a non-null value when exiting constructor. Consider declaring the property as nullable
With nullable reference types enabled, a non-nullable reference property isn’t initialised by the constructor.
Swift: Reference to property 'x' in closure requires explicit use of 'self' to make capture semantics explicit
In an escaping closure inside a class, Swift requires self. to make the capture (and potential retain cycle) visible.
Go: declared and not used: x / "fmt" imported and not used
Go refuses to compile code with unused local variables or unused imports.
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