The drive is properly mounted and has no security issues. I can log on with SFTP and Putty and see the drive and data (all with 777 permissions). If I create symbolic links (ln -s) from the Sandisk Thumb Drive into the Volumio Music directory, it has no problems cataloging and playing the music. This is, however, tedious.
Raspberry Pi 2 B+
Sandisk 8gb MicroSD card with the Volumio2 download
Volumio 2.175 with YouTube plugin
HiFiBerry DAC+ Pro
Sandisk 32 GB U1 Thumb Drive
Please, let me know if you need other information to look into this problem. Heck, if you want I can pull the MicroSD card image and you can play with it at your leisure. Although I am, at some point, going to reset it back to ‘factory settings’, reboot, and go through my setup again because it (getting music from the Thumb Drive) did work at one time and doesn’t now.
Even with this and one other weirdness having to do with the YouTube plug in, I am thrilled with Volumio, works great and the web radio works mostly very well. Thanks guys and gals.