diff -r d3e9f3423ef3 -r 071dcdf33f86 share/hedgewars/Data/Missions/Challenge/Basic_Training_-_Sniper_Rifle.lua
--- a/share/hedgewars/Data/Missions/Challenge/Basic_Training_-_Sniper_Rifle.lua	Wed Mar 07 23:52:45 2018 +0100
+++ b/share/hedgewars/Data/Missions/Challenge/Basic_Training_-_Sniper_Rifle.lua	Thu Mar 08 00:18:32 2018 +0100
@@ -113,7 +113,8 @@
 	-- The base number for the random number generator
 	Seed = 0
 	-- Game settings and rules
-	GameFlags = gfMultiWeapon + gfOneClanMode + gfArtillery
+	ClearGameFlags()
+	EnableGameFlags(gfMultiWeapon, gfOneClanMode, gfArtillery)
 	-- The time the player has to move each round (in ms)
 	TurnTime = 150000
 	-- The frequency of crate drops