It is not only about vista. There is an intersystems web server in play here that I am not sure I am properly communicating with long before it would hit vista. I asked what kind of URL Intersystems is expecting in a POST, how people are interacting via postman and what their requests look like, and what is really going on under the hood of the web server in these cases. How people typically resolve 403 errors would be a great place to start. There is plenty to talk about here that isnt about vista.