Try this.
Index: java/org/l2jmobius/gameserver/model/holders/SummonRequestHolder.java
===================================================================
--- java/org/l2jmobius/gameserver/model/holders/SummonRequestHolder.java (revision 9736)
+++ java/org/l2jmobius/gameserver/model/holders/SummonRequestHolder.java (working copy)
@@ -32,7 +32,7 @@
public void setTarget(PlayerInstance summoner, Skill skill)
{
_summoner = summoner;
- _location = new Location(summoner.getX(), summoner.getY(), summoner.getZ(), summoner.getHeading());
+ _location = summoner == null ? null : new Location(summoner.getX(), summoner.getY(), summoner.getZ(), summoner.getHeading());
_skill = skill;
}