Checksum mismatch on file ?

Edit: aaaand it's gone. Rest in peace, little hard drive.

Every once in a while, my DS720+ warns me that there's been a "checksum mismatch on file [ ]", as seen in the attached screenshot. What the fuck is that supposed to mean, what do I do with this? Why is there no file name?

Some context: One of my drives seems to be failing, maybe, possibly, and I'd been getting similar checksum mismatch warnings but they'd at least include a path and filename (as far as I can tell they were all temp files). SMART data tells me there are bad clusters, but different diagnostic tools have given me different results (the Seagate tool tells me the drive is perfectly healthy). A few days ago, I removed the drive and connected it to my PC, ran chkdsk on it, no issues. I put the drive back and put some data on it that I don't mind terribly losing to see what it's doing now. Since then, the warnings have been less frequent but they aren't giving me a file name anymore.

So I suspect these warnings are about that drive but now I'm out of ideas. I'm also fairly new at this stuff, bare with me. Anyone got any clues for me, please and thank you?