USTs Are Disappearing

[ArtsyP!nk]

So, while tuning one UST out of my collection, I got tired and saved the project. I came back the next morning only to find the UST empty. Like, there was nothing there at all. Why is this happening to my files? It's been happening for about a month without many ends, excluding my Reunion cover.

 

[Kiyoteru]

What folder are you saving your USTs in?

 

[ArtsyP!nk]

I've been saving my files in this folder named "Utau Stuff" and it's located in the downloads section of my computer.
I've had to clean it out with external drives two times due to space issues.