> ## Documentation Index
> Fetch the complete documentation index at: https://cometchat-22654f5b-docs-llms-scoped-indexes.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Troubleshooting

> Troubleshoot CometChat Calls SDK v5 on Android for setup, authentication, permissions, call launch, media, and session issues.

## Installation & Setup

| Symptom | Cause | Fix |
| - | - | - |
| Gradle sync fails | Repository not added or version mismatch | Ensure `maven { url 'https://dl.cloudsmith.io/public/cometchat/cometchat/maven/' }` is in your `build.gradle` |
| `init()` fails silently | Invalid App ID or Region | Double-check credentials from the [CometChat Dashboard](https://app.cometchat.com/) |
| Duplicate class errors | Conflicting WebRTC or transitive dependencies | Exclude conflicting modules in your `build.gradle` dependencies block |
| `minSdkVersion` error | SDK requires higher minimum API level | Set `minSdkVersion` to 26 or higher |

***

## Authentication

| Symptom | Cause | Fix |
| - | - | - |
| `login()` fails with invalid UID | UID doesn't exist in CometChat | Create the user via [Dashboard](https://app.cometchat.com/) or [REST API](/rest-api/users/create) first |
| Auth token expired | Token has a limited lifetime | Generate a new auth token and call `login()` again |
| `login()` called before `init()` | SDK not initialized | Always call `init()` and wait for the callback before calling `login()` |

***

## Joining a Session

| Symptom | Cause | Fix |
| - | - | - |
| `generateToken()` fails | User not logged in or invalid session ID | Ensure `login()` completes before generating a token |
| Session joins but no audio/video | Runtime permissions not granted | Request `CAMERA` and `RECORD_AUDIO` permissions at runtime before joining |
| `joinSession()` throws error | Invalid or expired token | Generate a fresh token using `generateToken()` before joining |

***

## Audio & Video

| Symptom | Cause | Fix |
| - | - | - |
| No audio from remote participants | Audio routing issue | Check [Audio Modes](/calls/android/audio-modes) for speaker/earpiece configuration |
| Camera not working | Permission denied or hardware issue | Verify `CAMERA` permission is granted and camera is not in use by another app |
| Echo or feedback | Speaker mode with no echo cancellation | Use earpiece mode or headphones |

***

## Background & VoIP

| Symptom | Cause | Fix |
| - | - | - |
| Call drops when app goes to background | No foreground service | Implement a foreground service to keep the call alive. See [Background Handling](/calls/android/background-handling) |
| VoIP notifications not working | FCM not configured | Set up Firebase Cloud Messaging. See [VoIP Calling](/calls/android/voip-calling) |
| App killed by OS during call | Missing foreground service notification | Show a persistent notification during active calls |

***

## Picture-in-Picture

| Symptom | Cause | Fix |
| - | - | - |
| PiP not working | Missing manifest attribute | Add `android:supportsPictureInPicture="true"` to your activity in `AndroidManifest.xml` |
| PiP not available on device | Android version below 8.0 | PiP requires Android 8.0 (API 26) or higher |


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