Hi there Frostedfoster,
I would advise you to back up the most important data that is stored on the drive until you sort the issue out.
You can start the troubleshooting process with checking the connections(cables/ports). You can switch the cables as well.
If the issue persists, then you should download a brand specific testing tool and test the drive. The results will show you whether there is something wrong with it.
Cheers,
D_Know_WD