Issue Duplicating Soundsets from Curse of Strahd

I’m having an interesting recurring issue that I’ve never seen before, and I was wondering if someone could help me out.

I’d like to customize some of the music and sound in Curse of Strahd: Death House, but I keep getting an error banner with “0-” every time I try to duplicate the Soundset (to make edits to the existing Soundset). I’ve duplicated plenty of Soundsets from Curse of Strahd before, but now I can’t duplicate any of them without receiving this error.

I’ve logged in and out, reset my browser, changed browsers, changed computers, and nothing seems to be working. I can copy Soundsets from other sources (like Deserted House) and create new, blank ones, but it appears I can’t duplicate from Curse of Strahd anymore.

Any help or feedback is greatly appreciated! Thank you!