SBox wont play Sound from USB Stick

Hi everyone
I have Set up everything properly i think, and SamplerBox even plays the default Sound when no USB Drive is plugged. But when i plug in my USB Drive, no Sound is playing.
Strange thing is that my USB Stick and the included .wav files are recognized by the raspi.
I used the Folder Structure as instructed in the FAQs and the MEDIA_DIR is set correctly to /media
maybe someone got an idea?
great project btw :)

Some people seem to be having issues with some USB sticks. For starters try a different one

thanks, ill do that!