If you are a new member or login on a new computer, please sync the history of all conversations or certain conversation group as follows:

PC:

Sync history

1. Click my profile and select "Local data".
2. Click the "Sync history" button.
   
    
3. Adjust the sync settings and click the "Start sync" button.
   

Sync the history of a certain conversation

1. Click "Chat history" in the upper left corner of chat window.
2. In the pop-up History window, click the down arrow to the right of Sync History.As shown below:
   
3. Set up sync options and click the "Sync" button.

App:

1. Enter a conversation group;
2. Click on the upper-right "···"  icon > "Project/Group Info" (member icon for individual chat groups);
3. Click "Sync History".