Why doesn't it work?

hi all

i got this problem in photoshop cs2

i’ve tried to add this filter effect to an image. except its not happening.

its basically a cross, and its a lighting effect, so it looks like a shining star.

however, when i mess with the filter settings…it looks good in the preview, but i press ok and nothing happens. in the history, it says its been done, but it hasn’t…