Occurred an error when execute SendbirdCall connectWebSocket()

[SDK Version]



I’m a user of Angular and Typescript, and using Calls SDK for Javascript.

The problem is occurred after successfully authenticated with Call server.

When I execute SendbirdCall.connectWebSocket(), I receive this error.

What can i do to fix this error?


 TypeError: Cannot read properties of null (reading 'readyState')
    at SendBirdCall.min.js:6:376395
    at new ZoneAwarePromise (zone.js:1429:1)
    at e.value (SendBirdCall.min.js:6:376277)
    at e.value (SendBirdCall.min.js:6:379586)
    at e.value (SendBirdCall.min.js:20:4971)
    at Function.value (SendBirdCall.min.js:20:13876)
    at call.services.ts:34:13
    at Generator.next (<anonymous>)
    at asyncGeneratorStep (asyncToGenerator.js:3:1)
    at _next (asyncToGenerator.js:25:1)

Here are my codes,

  • CallService Class
    export class CallService {
      user: SendbirdCall.User | undefined;
      init() {
        if (!APP_ID) return;
      async login(userId: string, accessToken: string) {
        // Authenticate with Call Server
        try {
          const user = await SendbirdCall.authenticate({
            userId: userId,
            accessToken: accessToken,
          this.user = user;
          console.log(`User Authenticated with Call server: ${user.userId}`, user);
        } catch (err) {
          console.log('Failed to authenticate with Call server \n', err);
        // Connect websocket to server
        try {
          await SendbirdCall.connectWebSocket();
          console.log('Succeed to connect to WebSocket');
        } catch (err) {
          console.log('Failed to connect to WebSocket \n', err);

  • AppComponent Class
    export class AppComponent implements OnInit {
      constructor(private callService: CallService) {}
      async ngOnInit() {
        await this.callService.login(

I resolved this problem by using version 1.9.3

I think it is a issue of latest updated version…