<step>

1. go to the playback on Live 16screen mode(default)

2. click one channel you want

3. open screen mode toolbar with Mode button or << button on the right side

4. click 1screen mode button

5. click ‘<' or '>’ button to move to next channel → changed channel shows “No Data” on the bottom

6. click ‘all' screen mode button → all channels shows No Data even when you move the timeline, except for the channel that was changed to 1screen mode at first

*C3CMS has the same symptom.