Help with Minimap

Hi, I made a minimap pic, size 256x256, 16 bit, and i imported it to war3mapPreview.tga, and then, when i look for it on the create game list, my game shuts down, and gives a access violation error message, i am using photoshop, can anyone tell me what im doing wrong?

Did you create the image from scratch or used al old TGA as base?

The way i made it is i opened warcraft, took a screenshot, and edited it with words etc. then turned it into tga

You might have to add an alpha channel to it, because i think it is converted right, but redoing all the process is always a good idea.

tga shuld be 32 bit