fixes #3828, thx MELERIX

L2_GameServer/java/config/l2jmods.properties

@@ -132,7 +132,7 @@ TvTEventParticipationNpcId = 70010
 # TvT Event Participation Fee (itemId, number). Fee is not returned.
 # Example: 57,100000
 # Default = none
-TvTEventParticipationFee =
+TvTEventParticipationFee = 0,0
 
 # Location for TvTEvent NPC to spawn.
 TvTEventParticipationNpcCoordinates = 83425,148585,-3406