> ## Documentation Index > Fetch the complete documentation index at: https://www.cometchat.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # Troubleshooting > CometChat Calling SDK v5 - Troubleshooting for JavaScript ## Installation & Setup | Symptom | Cause | Fix | | ------------------------------- | --------------------------------- | ----------------------------------------------------------------------------------- | | `CometChatCalls is not defined` | SDK not installed or not imported | Run `npm install @cometchat/calls-sdk-javascript` and import `CometChatCalls` | | `init()` fails silently | Invalid App ID or Region | Double-check credentials from the [CometChat Dashboard](https://app.cometchat.com/) | | `init()` throws network error | Region mismatch or network issue | Ensure the Region matches your app's region (`us`, `eu`, `in`, `in-private`) | | Module not found error | Incorrect import path | Use `import { CometChatCalls } from "@cometchat/calls-sdk-javascript"` | *** ## 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 `await CometChatCalls.init()` 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. Verify the session ID is valid | | `joinSession()` shows blank screen | Container element not found or not visible | Ensure the HTML element passed to `CallSettings` exists in the DOM and has dimensions | | Session joins but no audio/video | Permissions denied by browser | Prompt the user to allow camera/microphone access. See [Permissions Handling](/calls/javascript/permissions-handling) | | `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 output device issue or muted | Check speaker selection and ensure remote participants are not muted | | Camera not working | Another app is using the camera | Close other apps using the camera, or select a different device | | Black video tiles | Browser blocked camera access | Check browser permissions. HTTPS is required in production | | Echo or feedback | No echo cancellation | Use headphones or enable browser echo cancellation | *** ## Screen Sharing | Symptom | Cause | Fix | | ---------------------------------- | ----------------------------------------- | ------------------------------------------------------------------------------------------------------------------------- | | Screen share button not working | Browser doesn't support `getDisplayMedia` | Ensure the browser supports screen sharing. See [Browser Compatibility](/calls/javascript/overview#browser-compatibility) | | Screen share fails silently | User cancelled the share dialog | No action needed — this is expected behavior when the user dismisses the dialog | | Screen share not visible to others | Network or encoding issue | Check network connectivity and try reducing resolution | *** ## HTTPS & Deployment | Symptom | Cause | Fix | | --------------------------------------- | ---------------------------- | --------------------------------------------------------------------- | | Camera/mic permissions blocked | App not served over HTTPS | Use HTTPS in production. Localhost is exempt during development | | WebRTC connection fails behind firewall | TURN/STUN servers blocked | Ensure your network allows WebRTC traffic. Contact your network admin | | SDK works locally but not in production | Mixed content or CORS issues | Ensure all resources are loaded over HTTPS | *** ## Framework-Specific | Symptom | Cause | Fix | | -------------------------------------------- | --------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------- | | SSR error in Next.js | SDK uses browser APIs (`window`, `navigator`) | Use dynamic import with `ssr: false` or wrap in `useEffect`. See [Next.js Integration](/calls/javascript/nextjs-integration) | | Component renders but call UI doesn't appear | Container element not mounted yet | Ensure the DOM element is rendered before calling `joinSession()` | | Hot reload breaks call session | SDK state lost on HMR | Rejoin the session after hot reload, or disable HMR during active calls | *** ## Events & Callbacks | Symptom | Cause | Fix | | ------------------------- | --------------------------------------------- | ----------------------------------------------------------------------- | | Event listener not firing | Wrong event name or listener not registered | Check the [Events](/calls/javascript/events) page for exact event names | | Duplicate event triggers | Multiple listeners registered without cleanup | Remove listeners when the component unmounts or before re-registering | | `onUserJoined` not called | Listener registered after user already joined | Register listeners before calling `joinSession()` |