Nostalrius Begins - Quality wow vanilla realm (1.12)

Hello, just yesterday I was able to open up Nost just fine, but today when I try to open it I get a critical error message saying I don't have enough storage? I'm not sure if this is a problem with Nost or with my own computer, but some help would be greatly appreciated, thank you!

SS of the message https://www.dropbox.com/s/qgwd9ea57jg61 ... 3.png?dl=0

Probably your computer. I'll go ahead and ask the obvious; your HDD isn't out of space, is it? You could try installing WoW to a different location on your computer to see if it makes a difference; I've never really heard of anyone installing under the C:\Users\%username%\Downloads folder before.