In case someone else is having the same issues than what I am having, I also got the same 404 error. The quickest way I found to check was to go on the server itself, and open up “https://<servername>:8172/MsDeploy.axd”. Chrome & Firefox just showed a blank page, so I had to use the Network tab of the developer tools (F12) to see the actual 404 error message.

Somehow, while installing Web Deploy 3.0 from the Web Platform Installer, the IIS 7 Deployment Handler didn’t get installed, even though the IIS Manager UI Module did. In my case, I downloaded the Web Deployment Tool Installation .msi from the following link: Web Deployment Tool Installation. Then I had to go back to IIS Admin Tool (Start -> Run -> inetmgr.exe) > {server name} > click on Management Service icon, and restart the management service before the MsDeploy.axd handler started working.

Enabling IIS Deployment Handler + Remote Agent Service