Thunder VS 2015 - Failed to load the membership providers

Background
- Windows 10
- VS 2015 Community
- SF 9.2 installed through Sitefinity Project Manager
- Thunder Module activated in SF
- Thunder Extension installed in VS
- SF Running through IIS Express (Debug in VS)

Steps to reproduce
- VS Menu -> Telerik -> Thunder -> Connection Settings
- Add -> Put in the URL (http://localhost:60876) -> [TAB]
- Dialog immediately shows "Error occurred while connection to the server."
- VS Status bar shows "Failed to load the membership providers from MySite"

I've had this same issue on three different computers. I've uninstalled/reinstalled Thunder extension and module. I've turned off the Windows Firewall. I've checked the SF error log (no entries for this request).

What am I missing?

Hi Francesca,

did you ever get this resolved? I am having the exact same problem