Hi NGUYEN HAI NINH,
Sorry for the inconvenience.
I think, you may see license error when disconnecting your internet connection. Keep your net connection when editing Gallery Box.
If you need more help then please come with live chat.
Now I am online.
I have finished editing my website, do not do anything anymore, it’s ok this time. But then a few minutes later, my video gallery is not displayed, it requires to active again to display my gallery. Can you hepl me?