Sandisk Ultra 64G - using secureaccess - Unable to see the file saved on the drive

I am new using the secureaccess.  Yesterday, I update the secureaccess from version 1 to version 2 as instructed by the system.  I then saved a lot of files using the secure access utility.  I saw the spaces used on the USB drive went from almost nothing to 17G, that is about the size of the files I saved on the Sandisk USB drive.

Today, I plugged in the Sandisk USB drive into my PC again.  It asked me to update to version 2 again.  When I went into the vault, there are NO files displayed on the windows.  I checked the USB drive via my computer windows.  It showed about 17G information occupied the USB drive.

Someone please help me to recover those information…