Trouble with group chats — What can I do?
Like single chats, group chats are end-to-end encrypted in Threema. For privacy reasons, groups are not managed on our servers but directly on users’ devices. Since there is no information concerning group compositions stored on the server, groups can become asynchronous, e.g., if a user restores a data backup or is absent for an extended period of time.
If a group is asynchronous, we recommend resynchronizing it first. Only the group administrator can initiate a synchronization (in the group's detail view). Should the problem persist, please remove the group member due to which the group became asynchronous (see above), and add them again.
You can access a group's detail view as follows:
- Android: In the group chat, tap on the title bar.
- iOS: In the group chat, tap on the title bar, and then tap on the bar that appears underneath it (containing tokens of the group members).
- Windows Phone: In the group chat, tap on “…”, and then tap on “group details”.
If some members cannot see messages in a group chat, it is usually because they have activated the option “Block Unknown”. Disable the “Block Unknown” option in Threema > Settings > Privacy to receive all group-chat messages.