<!--
{
  "availability" : [
    "iOS: 9.0.0 -",
    "iPadOS: 9.0.0 -",
    "macCatalyst: 13.1.0 -",
    "visionOS: 1.0.0 -",
    "watchOS: 2.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "WatchConnectivity",
  "identifier" : "/documentation/WatchConnectivity/WCError/Code",
  "metadataVersion" : "0.1.0",
  "role" : "Enumeration",
  "symbol" : {
    "kind" : "Enumeration",
    "modules" : [
      "Watch Connectivity"
    ],
    "preciseIdentifier" : "c:@E@WCErrorCode"
  },
  "title" : "WCError.Code"
}
-->

# WCError.Code

Constants for errors during a session.

```
enum Code
```

## Topics

### Error Codes

[`WCError.Code.genericError`](/documentation/WatchConnectivity/WCError/Code/genericError)

An error that occurs when there is an unknown problem.

[`WCError.Code.sessionNotSupported`](/documentation/WatchConnectivity/WCError/Code/sessionNotSupported)

An error indicating that the current device doesn’t support the use of session objects.

[`WCError.Code.sessionMissingDelegate`](/documentation/WatchConnectivity/WCError/Code/sessionMissingDelegate)

An error indicating that the WatchKit extension doesn’t have a valid extension delegate to process events.

[`WCError.Code.sessionNotActivated`](/documentation/WatchConnectivity/WCError/Code/sessionNotActivated)

An error indicating that the other device doesn’t have an active session.

[`WCError.Code.deviceNotPaired`](/documentation/WatchConnectivity/WCError/Code/deviceNotPaired)

An error indicating that the current device doesn’t have a paired counterpart.

[`WCError.Code.watchAppNotInstalled`](/documentation/WatchConnectivity/WCError/Code/watchAppNotInstalled)

An error indicating that the Watch app isn’t an installed app on the user’s Apple Watch.

[`WCError.Code.notReachable`](/documentation/WatchConnectivity/WCError/Code/notReachable)

An error indicating that the counterpart app isn’t reachable.

[`WCError.Code.invalidParameter`](/documentation/WatchConnectivity/WCError/Code/invalidParameter)

An error indicating that a parameter is invalid.

[`WCError.Code.payloadTooLarge`](/documentation/WatchConnectivity/WCError/Code/payloadTooLarge)

An error indicating an attempt to send an item that exceeds the maximum size limit.

[`WCError.Code.payloadUnsupportedTypes`](/documentation/WatchConnectivity/WCError/Code/payloadUnsupportedTypes)

An error indicating that a dictionary contains nonproperty list types.

[`WCError.Code.messageReplyFailed`](/documentation/WatchConnectivity/WCError/Code/messageReplyFailed)

An error that occurs when the system can’t return the reply.

[`WCError.Code.messageReplyTimedOut`](/documentation/WatchConnectivity/WCError/Code/messageReplyTimedOut)

An error that occurs when the counterpart app doesn’t return a reply in time.

[`WCError.Code.fileAccessDenied`](/documentation/WatchConnectivity/WCError/Code/fileAccessDenied)

An error indicating that the system can’t transfer a file because it is inaccessible.

[`WCError.Code.deliveryFailed`](/documentation/WatchConnectivity/WCError/Code/deliveryFailed)

An error that occurs when the system can’t deliver the payload.

[`WCError.Code.insufficientSpace`](/documentation/WatchConnectivity/WCError/Code/insufficientSpace)

An error indicating that there isn’t enough space on the receiving side to store the data.

[`WCError.Code.sessionInactive`](/documentation/WatchConnectivity/WCError/Code/sessionInactive)

An error indicating that the session is inactive.

[`WCError.Code.transferTimedOut`](/documentation/WatchConnectivity/WCError/Code/transferTimedOut)

An error that occurs when the transfer reaches the timeout limit before it completes.

[`WCError.Code.companionAppNotInstalled`](/documentation/WatchConnectivity/WCError/Code/companionAppNotInstalled)

An error indicating that the companion hasn’t installed the app.

[`WCError.Code.watchOnlyApp`](/documentation/WatchConnectivity/WCError/Code/watchOnlyApp)

An error indicating that the app is a watch-only app.


---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)