Fix custom content and importers blocking scripting reload

Source/Editor/Modules/ContentDatabaseModule.cs

@@ -88,6 +88,8 @@ namespace FlaxEditor.Modules
 
             // Register AssetItems serialization helper (serialize ref ID only)
             FlaxEngine.Json.JsonSerializer.Settings.Converters.Add(new AssetItemConverter());
+
+            ScriptsBuilder.ScriptsReloadBegin += OnScriptsReloadBegin;
         }
 
         private void OnContentAssetDisposing(Asset asset)
@@ -1260,6 +1262,47 @@ namespace FlaxEditor.Modules
             }
         }
 
+        private void OnScriptsReloadBegin()
+        {
+            var enabledEvents = _enableEvents;
+            _enableEvents = false;
+            _isDuringFastSetup = true;
+            var startItems = _itemsCreated;
+            foreach (var project in Projects)
+            {
+                if (project.Content != null)
+                {
+                    //Dispose(project.Content.Folder);
+                    for (int i = 0; i < project.Content.Folder.Children.Count; i++)
+                    {
+                        Dispose(project.Content.Folder.Children[i]);
+                        i--;
+                    }
+                }
+                if (project.Source != null)
+                {
+                    //Dispose(project.Source.Folder);
+                    for (int i = 0; i < project.Source.Folder.Children.Count; i++)
+                    {
+                        Dispose(project.Source.Folder.Children[i]);
+                        i--;
+                    }
+                }
+            }
+
+            List<ContentProxy> removeProxies = new List<ContentProxy>();
+            foreach (var proxy in Editor.Instance.ContentDatabase.Proxy)
+            {
+                if (proxy.GetType().IsCollectible)
+                    removeProxies.Add(proxy);
+            }
+            foreach (var proxy in removeProxies)
+                RemoveProxy(proxy, false);
+
+            _isDuringFastSetup = false;
+            _enableEvents = enabledEvents;
+        }
+
         /// <inheritdoc />
         public override void OnUpdate()
         {
@@ -1285,6 +1328,7 @@ namespace FlaxEditor.Modules
         public override void OnExit()
         {
             FlaxEngine.Content.AssetDisposing -= OnContentAssetDisposing;
+            ScriptsBuilder.ScriptsReloadBegin -= OnScriptsReloadBegin;
 
             // Disable events
             _enableEvents = false;