You have not connected the phone correctly. Phone's info should be read fully and correctly. To connect GT-I9505, perform the following steps:
1. Disconnect USB cable from phone.
2. Go to Menu->Settings->More->About Device.
3.Tap on "Build number" 7 times to enable developer options.
4. Go to Menu->Settings->More->Developer options.
5. Turn on "USB Debugging" option.
6. Go to dial window.
7. Enter "*#0808#" number.
8. Select "DM+Modem+ADB".
9. Press Home button.
10. Go to dial window.
11. Enter "*#9090#" number.
12. Set "Diag config" to "USB" value.
13. Restart phone.
14. Press "Read Info" in software.
Also, look here:
http://forum.gsmhosting.com/vbb/f684...8/#post9859847,
http://forum.gsmhosting.com/vbb/f684...6/#post9860927,
http://forum.gsmhosting.com/vbb/f684...2/#post9804911,
http://forum.gsmhosting.com/vbb/f684...ml#post9736060,
http://forum.gsmhosting.com/vbb/f684...6/#post9726100,
http://forum.gsmhosting.com/vbb/f684.../#post10346328.