Hi, I am using the Add Data widget in several apps. When adding a KML via the drop, it works in my workspace environment where I don't require a proxy to access the services. When the app is deployed to Test/Prod environments is uses the Esri resource-proxy to access the secured services, webmap, etc. I have rules in the proxy configured for
Sounds like it might be the security settings in Chrome. Have you tried with IE?
You can bypass Chrome security with the following command - start chrome.exe --disable-web-security