You can try restoring your flash drive by using the "Restore" tool:
First, back up all your data onto your computer or another drive.
Download the program from the following link: http://www.emtec-international.com/sites/default/files/drivers/restore.zip
If the Restore tool doesn't fix the issue, the flash drive should be returned to the store for a replacement.
Process to restore:
1) Plug in the flash drive (certify that only the EMTEC flash drive is plugged in)
2) Launch restore.exe
3) Press the RESTORE button
4) A warning message is displayed about erasing data. Press RESTORE to continue.
5) A confirmation message is displayed, then press YES.
6) A message RESTORING DEVICE... appears. Do not unplug the flash drive and wait for the restoration to complete (1 to 2 minutes).