Trouble saving envmap - greyed out

Hello, I’m trying to use this tutorial for making the textures of a skybox:

I’m now at the part where I should save the rendered envmap, but the option is greyed out together with the other options in the list. Any idea why this is happening? I used this same tutorial to create a skybox in 2.49, without this problem.

The skybox is going to be used in a unity project.


skybox.blend (1.69 MB)

UV unwrap cube. Then it generates env map and options are available.