.png textures messed up in Unity

Hey guys, I’ll try to explain this as well as I can.
For some reason, when I import a .png texture and apply it on a surface, it seems to be messed up as shown in the image below. The only workaround I found is to save it as a .jpg then back to a .png file again, which is quite a bit of work when dealing with many textures.

Does anyone know what is causing the problem? Any help is appreciated.

I guess That the Image should be transparent?
The right images shows the way of PNG to deal against artefacts.
If a image have a white and transparent surrounding PNG exported from photoshop get the surrounding filled with the color of the not transparent content to disable the “white glow” Effect around the edges.

If you do not like to use a transparent shader in unity you should make a white background layer behind the transparent image inside your Image editing tool.