That is weird as hell because nothing has changed in the files since that last update...
I just now extracted the files myself and it worked, could be a problem with winrar or something from what I see on google.
I succeeded by changing the folder and avoiding the extract all. I don't know what could have caused that but it worked in the end. The demo was nice by the way I hope you will have enough time/money to continue it.
What did you change? because I have the same problem.
I took the zip folder and extract it on my desktop instead of on a folder and use the excract option instead of the extract all
Thanks for responding! could you be more specific because I don't really understand what you mean.