I'm using WWW to get data from a server in a coroutine. This works fine in the editor targeting webplayer, but fails in webplayer on firefox 38.0.5. WWW.error returns: Code (C#): Failed downloading http://myserver.../myphpfile.php All the other instances of this error I've been able to find refer to the actual webplayer page not being able to find the webplayer plugin, which is not the case here. Here, the webplayer loads fine, but when the WWW call tries to get the data from the server via POST to the PHP page, it returns this error inside the app. I'm at wit's end here, and I have no idea why this should work in the editor but not in the webplayer. I've added the exact URL of the webplayer to the security settings in Editor Settings, of course. The URL is not relative, it's hard coded. The editor is getting data back from the live server that the webplayer should be targeting, not a test server or localhost. I can open the php page on the server and see that it's there. I have a crossdomain.xml at the root of the server. I tried adding a web.config file, but it didn't do anything (and it seemed that was the resolution to the unity file itself not being recognized, so shouldn't have worked anyway) I'm calling in an airstrike. I need Eric5h5, Dreamora, or andeeee's expertise. This is mission-critical for me, and I have an entire project riding on the concept of being able to store data on this server. Halp.