Fix crash

tournaments/models/team_score.py

@@ -14,11 +14,14 @@ class TeamScore(models.Model):
         return f"{self.match.stage_name()} #{self.match.index}: {self.player_names()}"
 
     def player_names(self):
+        if self.team_registration:
             if self.team_registration.name:
                 return self.team_registration.name
             else:
                 names = self.team_registration.team_names()
                 return " - ".join(names)
+        else:
+            return "--"
 
     def team_names(self):
         names = []