Sonoma Partners Microsoft CRM and Blog

CRM 2011 Plugin Registration Error on Connect: 407 Proxy Authentication Required

Today's guest blogger is BJ Dibbern, a Developer at Sonoma Partners.

I stumbled across a weird error the other day when trying to use the CRM 2011 Plugin Registration Tool to register a plugin assembly in a new On-Premise environment. I fired up the Plugin Registration Tool and setup all my connection information, however when I hit Connect I received this error almost immediately: “The remote server returned an error: (407) Proxy Authentication Required."


First things first, I checked that I didn’t still have Fiddler running. Fiddler can cause these kind of errors, but sadly Fiddler was not running at the time so I knew it was a different problem. Checking on Fiddler actually gave me an idea though to start up Fiddler and see if any requests were being made from the Plugin Registration Tool.

What I found was that when I would click Connect, the tool would try to open a tunnel to


This was quite surprising to me as I was not expecting any interaction with any external services, even, considering it was an On-Premise deployment I was attempting to connect with. After seeing this behavior, I opened up Internet Explorer and found I also could not connect to that site from the browser. Rather than mess with the firewall settings, I decided to see if I could work around it.

Apparently the first time you run the Plugin Registration Tool on a new machine or under a new user account, the tool tries to hit Microsoft’s Live services for a new Device Id. Since I had another machine that’d already worked, I figured I might be able to copy the Xml file the tool was looking for over to the target machine. Thankfully, this worked! All I had to do was copy LiveDevice.xml from the source machine’s %userprofile%\LiveDeviceId\ folder to the target machine’s same folder.

Note that at the time I was connecting to an On Premise environment and not a CRM Online environment. However, I would doubt that this would help in that scenario as if you cannot access, chance are you’ve got some bigger changes to make to your firewall or proxy server so that you can access