-fix- Android File Transfer “Can’t access Device Storage”

Open the Developer Options on your Jellybean i9300 and disable “Verify Apps by USB”

“Verify apps over usb — Allows you to disable app checks for sideloading apps over USB, while still checking apps from other sources like the browser. This can speed up the development process while keeping the security feature enabled.”

System: 10.9.2 / Foxhound 1.0 , but it should work with most other Jellybean variants.