HELP! My skybox does not show up, it's a completely black skybox.
Please provide a link to your project.
The problem is that your cubemap face images are all different sizes and some are not square. Please read this thread.
Each of texture face for cubemap, should be identical square size. So if you resize all textures to lets say 1024x1024, then it will be ok.
Probably need to add warning message, to indicate such scenario.
Ohhhhh.....duh. Wow, thank you very much!
We've added some info message below face picker in CubeMap Inspector, which gives information about what is required to get complete CubeMap.