Please confirm from the following aspects:

• Ensure that the receiver has correctly implemented the corresponding IM callback interface.
• Make sure that the sender and receiver use the same appID and roomID.
• ZEGO IM messages are real-time online messages, and the sender/receiver must be online at the same time (login to the room is successful).
• The sender cannot receive the IM message sent by the local end.

When logging in to the room, the input format of the "token" parameter is incorrect, causing the error. "token" is a string type, and the JSON format needs to be encrypted with base64 and then passed in loginRoom interface, please refer to Quick start doc for specific implementation.

There are two possible reasons for this error:

• AppID expired.
• Server address is wrong, please go to ZEGOCOUD Admin Console to confirm.

• If you call "logoutRoom" to exit the main room, or are kicked out of the room by a background service, the SDK will automatically stop the push and pull stream.
• If you call "logoutRoom" to exit the multi-room, the SDK will not automatically stop the push and pull streaming.

Developers need to refer to the above logic and process the logic to stop the push and pull flow according to business requirements.

1. Upgrade Express-SDK to 1.13.0 or above;
2. Please contact ZEGO technical support to apply to open the multi-room function.

The error code "1002001" means that the user cannot log in to multiple rooms at the same time. Before logging in to a new room, you need to call "logoutRoom" to log out of the current room, otherwise the SDK will determine that the current user has logged in to multiple rooms, and this error will occur.

• Before switching rooms, you need to call "loginRoom" to log in to room A before you can use "switchRoom" to switch to room B.
• If the "fromRoomID" parameter used is inconsistent with the "roomID" the user is currently in when calling "switchRoom", this error will also occur.