Storage connection problem

I’ve been using Roon for a few years and it is running fine.

Today I accidentally find out the the storage I am using, WD My Book Duo, is not available when I go to the Storage tab. It is connecting to my Roon server (Intel nanoPC) through USB port. I still can listen to my music collection daily.

I am wondering how can I play the music when the hard drive is not available. How can I reconnect it back?