Unable to make background invisible in PS

Hello kgirly19

When saving as DDS on a mac you need to select the format in an additional window afterwards.
There you need to select: DXT5 and tick the tickbox for mipmap. Leave the rest as is.

Or you simply save as png and import that, it works as well.

About the preview, there is a preview issue on Candy Apple and CAS items I am unsure until which extend it goes but it could be it applies as well for simple texture changes.
To fix this and force S4S into actualising the preview, you can save your project after import. Close it and reopen it, it should update the preview.

The devs are aware of the issue.

For the turning black when moving the issue, it's probably linked and might be fixed with the next patch. In the meantime you can simply not move the window around :p