when a exception occurs, or 404 not found happens, it does not display the yellow error page as usual, but some gibberish

The website is English & Traditional Chinese version; everything works fine on other machines.

The problem is as follows:
My operating system: Windows Server 2008 R2 (Traditional Chinese).
The website can operate normally,
but when a exception occurs, or 404 not found happens, it does not display the yellow error page as usual, but some gibberish (in chrome browser), in IE browser display a file download.

http://img.my.csdn.net/uploads/201212/25/1356405716_8872.jpg