I’m in the process of planning a SP2007 to SP2010 ‘migration’ moving over the content database and other web artifacts.

I was making sure all things were ticked off and available in the new SP2010 environment such as – additional external scripts, paths, externally accessible images, webparts + flash movie files.

Migrated over – fired up the browser and after some minor tweaking most things came over, except for the flash movies.

The flash movie was not being displayed.

So naturally you think – must be a path, permission, activeX, flash object declaration, upload or even a masterpage might need a tweak…

Fired up FireBug in firefox and went to work – we could access the *.swf file directly from within the browser, but when the Page loaded with the link in there… no go.

In fact we got a ‘304 not modified’ response within FireBug – which seems pretty normal if the flash player already has the movie locally and it’s just comparing the server version versus the local…but still no flash playing.

SharePoint 2010 Web Applications restrict ‘active’ content – aka Flash out of the box.

After some digging and a seemingly unrelated option appeared in Web Application –> General Settings.
Browser File Handling - Default setting: STRICT

This was the culprit, setting this to permissive did the trick.

Wow! Have a great weekend folks!