Batch file error when generating mod for Steel Division 2 – might be DirectX related

I'm trying to generate a mod for Steel Division 2 on Windows 10, but I'm getting an error I've never seen before. I've run the same process many times in the past without any issues—until today.

Earlier I was messing around with an ISO trying to get an old Windows XP game to run, and I suspect I may have broken something with DirectX in the process. I've already tried reinstalling DirectX and clearing the cache, but that didn't help.

One thing I'm wondering is whether mounting that ISO created some kind of virtual drive that's now interfering—though I checked Disk Management and didn't see anything unusual.

Part of the error message is in French (Eugen Systems is a French studio), which is making it even harder to figure out what's actually wrong. Anyone run into something similar or have any idea what might be causing this?