I was with the same issues and I managed to fix it by converting disk from MBR to GPT layout
you can use MiniTool Partition Wizard ( http://www.partitionwizard.com/free-partition-manager.html ), I’ve done it using DISKPART windows utility. You can convert it back to MBR if you want.
FYI, backup everything, you will have to delete all the data from the flash drive
