UTAU won't generate a wav file

[GumiSilverLovah]

I've been using UTAU for a long enough time, but this has never happened before. I went to render a UST I made to test it out, but after saving it and playing it a few times in UTAU, I got the message "Failed to generate wav file. Please check settings." and it only does that with USTs I've made myself.

I don't think there's anything wrong with my resampler, since I'm able to play the UST in UTAU perfectly fine.

Does anyone have a clue what could be causing it?