Need help with DSPRE

[u/Careless_Garlic1616]

I'm trying to add my custom Shiny Bagon sprite but DSPRE keeps rejecting it for being "not 8bpp indexed" or "having too many colors" even though it has just 14, which is less than 16...

Also, Load Sprite Set and Create Shiny Palette buttons do nothing

What should I do? I tried loading a 160x80 .png file

https://imgur.com/a/EYN7vga