diff -u -r u4-format-security/src/screen_sdl.cpp u4/src/screen_sdl.cpp
--- u4-format-security/src/screen_sdl.cpp	2015-01-23 21:44:46.000000000 -0600
+++ u4/src/screen_sdl.cpp	2015-02-22 15:59:04.665560535 -0600
@@ -257,7 +257,7 @@
 
 	screenRefreshThread = SDL_CreateThread(screenRefreshThreadFunction, NULL);
 	if (!screenRefreshThread) {
-		errorWarning(SDL_GetError());
+		errorWarning("%s", SDL_GetError());
 		return;
 	}
 }