I've been scratching my head for hours trying to figure out why my canvas page is returning a 405, I don't know if POST or SSL is the culprit but I know I cant be the only one trying to creating a facebook canvas app.

I haven't found anything other than the following links.

http://blogs.msdn.com/b/benjguin/archive/2012/06/22/deploying-the-need-facebook-canvas-app-to-windows-azure-web-sites-d-233-ploiement-de-l-appli-canvas-facebook-dans-les-web-sites-windows-azure.aspx

This doesn't work for me it still returns 405

I'm running on a reserved instance,

with a custom domain name,

I set the canvas url to    http://myapp.azurewebsites.net/ and secure canvas to https://myapp.azurewebsites.net/

I can go to www.myapp.net and the http://myapp.azurewebsites.net no errors,  however going to my canvas page https://apps.facebook.com/myapp

 returns 405. 

Does anyone know how to fix this?

See this blog:

http://blog.smarx.com/posts/custom-domain-names-in-windows-azure

Make sure your CName is OK in Azure.

My cname is fine, As I stated it works outside of facebook.  but throws 405 in the facebook iframe.

I have made the mistake 2 times of creating my canvas app with an html extension instead of using a scripting extension. For example, if you are running on a Windows server and coding in Visual Studio, it is tempting to just create .htm or .html files.  However, most web servers will not allow a POST operation to these pages. Instead, create .aspx pages, which will still allow you to use the same exact static HTML and JavaScript.  This solved my problem in both cases.