Index: src/main/java/org/bukkit/craftbukkit/CraftServer.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java	(revision 2092b553cf3dbfc5fbe5534ac1bfd42e2c90a9fc)
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java	(date 1609100597313)
@@ -351,13 +351,25 @@
 
         if (pluginFolder.exists()) {
             Plugin[] plugins = pluginManager.loadPlugins(pluginFolder);
+            List<Thread> threads = new ArrayList<>();
             for (Plugin plugin : plugins) {
-                try {
-                    String message = String.format("Loading %s", plugin.getDescription().getFullName());
-                    plugin.getLogger().info(message);
-                    plugin.onLoad();
-                } catch (Throwable ex) {
-                    Logger.getLogger(CraftServer.class.getName()).log(Level.SEVERE, ex.getMessage() + " initializing " + plugin.getDescription().getFullName() + " (Is it up to date?)", ex);
+                Thread thread = new Thread(() -> {
+                    try {
+                        String message = String.format("Loading %s", plugin.getDescription().getFullName());
+                        plugin.getLogger().info(message);
+                        plugin.onLoad();
+                    } catch (Throwable ex) {
+                        Logger.getLogger(CraftServer.class.getName()).log(Level.SEVERE, ex.getMessage() + " initializing " + plugin.getDescription().getFullName() + " (Is it up to date?)", ex);
+                    }
+                });
+                thread.start();
+                threads.add(thread);
+            }
+            for(Thread thread : threads){
+                try {
+                    thread.join();
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
                 }
             }
         } else {