From 3e4bc05dc705bde343e9e903efc308c53187d4cd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rafa=C5=82=20Chomczyk?= <rchomczyk@icloud.com>
Date: Mon, 25 Dec 2023 18:20:14 +0100
Subject: [PATCH] Fix concurrent exception with Sidebar#addViewers

---
 src/main/java/me/catcoder/sidebar/Sidebar.java | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/main/java/me/catcoder/sidebar/Sidebar.java b/src/main/java/me/catcoder/sidebar/Sidebar.java
index 741b225..3ebda62 100644
--- a/src/main/java/me/catcoder/sidebar/Sidebar.java
+++ b/src/main/java/me/catcoder/sidebar/Sidebar.java
@@ -394,14 +394,15 @@ public void addViewer(@NonNull Player player) {
         if (!viewers.contains(player.getUniqueId())) {
             objective.create(player);
 
-            for (SidebarLine<R> line : lines) {
-                line.createTeam(player, objective.getName());
+            synchronized (lines) {
+                for (SidebarLine<R> line : lines) {
+                    line.createTeam(player, objective.getName());
+                }
             }
 
             objective.display(player);
 
             viewers.add(player.getUniqueId());
-
         }
     }