Obviously it’s a newer device in which case not U3 compatible. SanDisk stopped manufacturing U3 devices several years ago. If security is your concern try the new security app SecureAccess. http://forums.sandisk.com/t5/Cruzer-flash-drives-Solid-State/SanDisk-SecureAccess-Password-and-encryption-software/td-p/217852
And if that’s not the problem, I suggest you return the device to the store and get a new one. 
