when i try to make the <mapname>_ground.bitmap on tool with the original TIF file it wont work and give me the alpha error like its soupposed to

.but since that didnt work i got the TIF file from my splinter tutorial folder(i used the splinter TIF file on the map so i thought it would work).it gave me the error but when i try to do the alpha thingy on guerilla it tels me this.

what do i do and how do i get tool to compile a ground.bitmap file.