My Android File Transfer was working just fine yesterday, but now it only recognizes files on my "phone" but not on my "card". When I click on the "card" tab a window pops up with a message similar to "if your device is locked, unlock and reconnect USB". My phone is unlocked and I even tried in the "debugging" mode. I have also restarted my device (MacBook Pro) several times. I am using a Galaxy S4. Help!