Skyboxes not working. Game bug?

[Mudbill]

Hello,
I have a somewhat strange problem here. I'm thinking it could be something with the game or the way Amnesia handles dds files on a Mac.

I have a Mac with a Windows partition, so I can use either if I need to. Because the Nvidia plugin for Photoshop (used for creating .dds skyboxes) is only for Windows I went on there, created one and put it into my map.
It took a lot of tweaking, but I did get it working in the end and it looked great.
However, as soon as I go back to the Mac partition, the dds file no longer works in the game. It appears to work in the editor when I select the file, but when I save the map and open it in-game, the sky is plain white.

Some comparison images from the editor and game (I'm using the exact same level and assets in both):

Spoiler below!

Mac:




Windows:

As I said, the skybox works perfectly on Windows, so it shouldn't be anything wrong with the file or process.

It seems that even if I input the skybox.dds into the Level Settings in the editor, it remains blank after saving and reopening. Perhaps the problem is that it's never saved, instead of the game having trouble displaying it.

If anyone knows anything about this, please respond. I'm not excluding the fact that this could be a problem in the Mac version of the editors, but I certainly hope it isn't.
Thank you for any answers.