Files not found on former NAS drive

I had a 1.5 TB drive within my Linksys NAS storage device and now I’m unable to access the files.  No folders are found but the NAS software shows the amount of storage taken up and the free space by the drive.  

I’ve worked with Linksys to obtain a new NAS box but the files are still not found.  I’ve tried to connect the drive to several other computers both via USB and wired to the mother board.  The drive is recognized but still unable to view these files.  As you might imagine they are important files which I don’t want to lose.

Any help would be appreciated.

Thanks

are you inquiring about a Linksys router or a WD drive?

The WD drive