Today, the SWF label of the Flex project is replaced with swfobject. During debugging, the blocking prompt is always displayed in IE. Therefore, I added a simple HTML comment, and IE was quiet:
<! -- Save from url = (0014) about: Internet -->
For a detailed explanation of this comment, refer to msdn.
Add a "saved from URL" comment to the local HTML file to indicate that Internet Explorer applies the settings of other regions to the HTML content on the local computer. For example, you can add a "saved from URL" comment to a local HTML file so that the HTML file can be allocated to the Internet area rather than the local computer area. If you allow scripts, signed ActiveX controls, and Java applets in the Internet, the local HTML file runs with these reduced security permissions.
To instruct Internet Explorer to use the internet region for a local HTML file named test.htm, add the following comment to test.htm. Add the comment using a single line before marking.