Hi I'm new here, need some assistance with custom tile sets.

Recently combined and made a custom tile set, all's pretty much okay till I imported it into the RPGmaker.
The problem I had was that when I imported the tile set the Preview interface did not appear. So ended up being unable to set the background transparency colors. Keep deleting, adjusting and importing the tile set several times but the interface still doesn't appear.

Am I doing something wrong with the custom tile set? Been using Photoshop to do the tile set, and usually saving it as a PNG file.

If rpg maker doesn't bring up the preview, then the image is probably already transparent.

If you set even a single point with transparency different from default, RPG Maker won't let you import the image with the preview window, even if it is a PNG file.
You should erase the background manually with Photshop or Paint.NET OR be sure there's no transparency set in your file (it can just be a single-pixel issue)

I hope this can help...

Jens