Legacyshader.fxo "file not found"

thanglu56

i started playing crossfire and during the game about 20 mins or staying lobby, i get this "send error report" and i click ok. then that thing pops up File not found legacyshader.fxo... anyone have a solution?
here's a picture:
http://gyazo.com/3ac46d2533345f57285d1da8a7fc8b33
FYI, when i use integrated graphics, i "dont get that error" BUT..... if i use "nvidia graphic" then i would get that error.