# SDK error codes (/en/realtime-media/voice/reference/error-codes/unity)
> For AI agents: see the complete documentation index at [llms.txt](/llms.txt).
When interacting with the Agora API, the Voice SDK may return an error code. Receiving an error code indicates that the SDK has encountered an unrecoverable error that requires intervention from your app.
This page provides descriptions for common error codes, their causes, and suggested solutions. For error codes without predefined solutions, [contact technical support](https://agora-ticket.agora.io/) for assistance.
The error codes listed in this section apply to Agora RTC v4.x SDK on the following platforms:
* Native platforms: Android, iOS, macOS, Windows
* Third-party frameworks based on native platforms: Electron, Unity, React Native, Flutter
During SDK operation, error codes may be returned in the following ways:
* In the return value of a failed method call
* Through the `onError` callback
- When the SDK returns an error code, it may return a negative number. This negative number corresponds to the positive integer in the error code. For example, if it returns `-2`, it corresponds to `2` in the error code.
- The API names in this article are based on the C++ API. The API names for other platforms may be different. Refer to the API documentation for the corresponding platform.
## Common error codes [#common-error-codes-8]
| Error code | Description |
| :--------: | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `1` | General error with no clearly categorized cause. Call the method again. |
| `2` | An invalid parameter was set in the method. For example, the specified channel name contains illegal characters. Reset the parameters. |
| `3` | The SDK is not ready yet. Common reasons include failed `RtcEngine` initialization, calling a method before joining a channel, calling `rate` or `complain` before leaving a channel, the audio module not being enabled, or incomplete assembly. |
| `4` | The current state of `RtcEngine` does not support this operation. Common reasons include setting an incorrect built-in encryption mode or failing to load the external encryption library. |
| `5` | The method call is rejected. Common reasons include failed `RtcEngine` initialization, an empty channel name when joining a channel, or reusing an existing channel name in a multi-channel use case. |
| `6` | The buffer size is not large enough to hold the returned data. |
| `7` | The method is called before `RtcEngine` is initialized. Make sure the `RtcEngine` object has been created and initialized before calling the method. |
| `8` | The current state is invalid. Check the SDK callback logs to find the exact reason. |
| `9` | There is no permission to operate. Check whether the user has granted the app permission to use audio or video devices. |
| `10` | Method call timed out. Some method calls require the SDK to return results, and this error occurs if the SDK takes too long to process the event and does not return for more than 10 seconds. |
| `17` | Joining a channel is rejected. The user may already be in the channel, or an echo test may still be running. Agora recommends using `onConnectionStateChanged` to determine whether the user is in the channel, and calling `stopEchoTest` before joining after an echo test. |
| `18` | Failed to leave the channel. The user may already have left the channel, or the leave method may have been called before the user joined. |
| `19` | The resource is occupied and cannot be reused. |
| `20` | The SDK abandons the request, possibly due to too many requests. |
| `21` | Specific firewall settings on Windows cause `RtcEngine` initialization to fail and then crash. |
| `22` | The SDK failed to allocate resources, possibly because the app takes up too many resources or the system resources are exhausted. |
| `101` | Not a valid App ID. Rejoin the channel with a valid App ID. |
| `102` | Not a valid channel name. The parameter data type may be incorrect. Rejoin the channel with a valid channel name. |
| `103` | Cannot get server resources for the current region. Try to specify a different region when initializing `RtcEngine`. |
| `109` | The currently used token has expired and is no longer valid. Generate a new token on the server side and call `renewToken` to update the token. |
| `110` | Token is invalid. Common reasons include enabling the App Certificate without using token authentication, or using a token whose `uid` does not match the `uid` used to join the channel. |
| `111` | The network connection is interrupted. After the SDK established a connection with the server, the network connection was lost for more than 4 seconds. |
| `112` | Network connection lost. The network connection was interrupted and the SDK could not connect to the server within 10 seconds. |
| `119` | User failed to switch roles. Try joining the channel again. |
| `120` | Decryption failed. The user may have used the wrong password when joining the channel. Check the password the user entered when joining the channel, or ask the user to rejoin. |
| `121` | The user ID is invalid. |
| `123` | This user has been banned by the server. This error is reported when the user is kicked out by the server. |
| `134` | Invalid user account, possibly because invalid parameters are set. |
`109` is deprecated. The SDK returns `CONNECTION_CHANGED_TOKEN_EXPIRED(9)` in `onConnectionStateChanged` instead.
`110` is deprecated. The SDK returns `CONNECTION_CHANGED_INVALID_TOKEN(8)` in `onConnectionStateChanged` instead.
## Audio-related error codes [#audio-related-error-codes-8]
| Error code | Description |
| :--------: | --------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `1005` | An unspecified error occurred in the audio device. Check if the audio device is occupied by another application or try to re-enter the channel. |
| `1008` | An error occurred while initializing the playback device. Check if the playback device is occupied by another application or try to re-enter the channel. |
| `1009` | Error starting the playback device. Check if the playback device is working properly. |
| `1010` | Error stopping the playback device. |
| `1011` | Error initializing the recording device. Check if the recording device is working properly, or try to re-enter the channel. |
| `1012` | Error starting the recording device. Check if the recording device is working properly. |
| `1013` | Error stopping the recording device. |
## Data stream-related error codes [#data-stream-related-error-codes-8]
| Error code | Description |
| :--------: | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `113` | The user was not in the channel when the `sendStreamMessage` method was called. |
| `114` | The length of the data sent was greater than 1024 bytes when `sendStreamMessage` was called. |
| `115` | The frequency of sending data exceeded the limit of 6 KB/s when calling `sendStreamMessage`. |
| `116` | The number of data streams exceeded the limit of 5 when `createDataStream` was called. |
| `117` | Data stream send timeout. If reliable or ordered data is not received within 5 seconds, or missing data is detected, `onStreamMessageError` is triggered on the receiving end. |
## Other error codes [#other-error-codes-8]
| Error code | Description |
| :--------: | ---------------------------------------------------------------------------------------- |
| `130` | The SDK does not support pushing encrypted streams to a CDN. |
| `1001` | Failed to load the media engine. |
| `1501` | There is no permission to use the camera. Check if camera permission has been turned on. |