Installing SecureAccess 3.0 on Mac OS X El Capitan

Good morning.  I apologize in advance if this has been addressed in a previous post; the only thing I could find was problems relating to SecureAccess 2.0.

I am trying to install SecureAccess 3.0 on a Mac running OS X El Capitan.  The USB drive in question is a 16 GB SanDisk Cruzer USB (standard).  Now, the instructions say to download the package directly to the flash drive, but I was under the impression we needed to actually install the SecureAccess software and the vault on the boot partition of the machine itself.  However, when running this software, the boot partition simply has a yellow warning sign that says “SecureAccess cannot be installed on this partition.”  The USB drive appears to work just fine.

Is this how it is intended to work, that we install everything on the flash drive and then drag files to the vault on the flash drive itself?