Authorization has been denied for this request - error message

This message is driving me crazy.....I am getting {"message": "Authorization has been denied for this request."} error message every-time I send a GET request.

Everything was working fine last week and suddenly this happened. I tested it on 5 different boxes and 3 different domains :( with no luck.

If I pass the request right in the browser, it works.

If I use google chrome POSTMAN, it also works. It is only with SoapUI.

What's wrong ?

BTW: my request is just a simple GET for ID's. None of my requests work in SoapUI.