This one crops up every-so-often, and a colleague just asked me again, so it’s probably worth posting. When an FLV is loaded into a Flash app, the FLV file is ‘played’ when the SWF or Projector is run. When this is done locally – i.e. you run an SWF from your hard drive, or file server – it’ll work fine. The problem comes when you upload it to your IIS web server. The server probably won’t recognise the ‘.flv’ filetype, so it’ll display nothing.

Solution

To make your IIS 6 web server aware of FLV files, do the following:
 

• Open ‘IIS Manager’.
• Right click on your site in ‘Web Sites’, and select ‘Properties’.
• Choose the ‘HTTP Headers’ tab.
• Click the ‘MIME Types…’  button on the bottom-right.
• Click ‘New…’ and then add ‘.flv’ and ‘video/x-flv’ as shown below:

Setting FLV Mime type in IIS site properties.

• ‘Ok’ your way out, and ‘Apply’ when needed.
• Your video should now play in a browser when embed in an SWF.