Here's my Player.log: xenosphere - Pastebin.com. I installed the redistributable but no joy I'm afraid
I've fixed it now and uploaded a new version: 1.0.4, which you can download on this page!
The explanation for the bug is, before I fixed it just now, my adaptive music software opened instruments with read/write access instead of just read access, which means the OS denies access since the "Program Files" directory is protected. Most people probably ran it from the desktop or download folder, which is why they weren't affected.
Thank you so much for giving me this log data! This has been helpful in a very big way, especially since this is a mistake in code I use in multiple projects.