sprites will not compile right

Everytime i add a sprite in hammer, for HL2, instead of the prerendered glow effect already showing, i get this black box around my sprites. and when compiling, they show up like that in game as well. If i load up a valve map, or any other map that I didnt create, then their sprites look normal in hammer, after clicking on their properties, then going back to my minimized map, and click on my sprites, my sprites turn back to normal, but still compile with the black box around them in-game. What does this mean? And how can i fix it?

Set the fx effects to additive.

edit: I mean the rendermode, set it to additive, or world glow

ok, i wasnt sure what those did, so i left them default, =didnt touch them, thanks i'll see if taht works :smile: