Displaying Chinese characters: some of them becomes to a block

I installed Amaya 9.52 for Windows.

When I input Chinese characters, some of chinese characters becomes to a hollow block.
This situation is very similar to the youtube.com.

for some examples:
1. the word "链接"(hyperlink) will displayed as "□接"
2. the word "游戏"(game) will displayed as "游□"
3. simply open http://www.chinaw3c.org page, you will see many hollow blocks