diff --git a/server/bundles/io.cloudbeaver.server/src/io/cloudbeaver/registry/WebObjectFeatureRegistry.java b/server/bundles/io.cloudbeaver.server/src/io/cloudbeaver/registry/WebObjectFeatureRegistry.java
index 15a6cc690d..af727ebf64 100644
--- a/server/bundles/io.cloudbeaver.server/src/io/cloudbeaver/registry/WebObjectFeatureRegistry.java
+++ b/server/bundles/io.cloudbeaver.server/src/io/cloudbeaver/registry/WebObjectFeatureRegistry.java
@@ -33,7 +33,7 @@ public class WebObjectFeatureRegistry {
 
     private final List<WebObjectFeatureProviderDescriptor> providers = new ArrayList<>();
 
-    public static WebObjectFeatureRegistry getInstance() {
+    public static synchronized WebObjectFeatureRegistry getInstance() {
         if (INSTANCE == null) {
             INSTANCE = new WebObjectFeatureRegistry();
             INSTANCE.loadExtensions(Platform.getExtensionRegistry());
diff --git a/webapp/packages/core-blocks/src/Tree/TreeNode/TreeNodeSelect.tsx b/webapp/packages/core-blocks/src/Tree/TreeNode/TreeNodeSelect.tsx
index 3361382d9e..c534f31063 100644
--- a/webapp/packages/core-blocks/src/Tree/TreeNode/TreeNodeSelect.tsx
+++ b/webapp/packages/core-blocks/src/Tree/TreeNode/TreeNodeSelect.tsx
@@ -16,7 +16,7 @@ import { TreeNodeContext } from './TreeNodeContext.js';
 import style from './TreeNodeSelect.module.css';
 
 interface Props {
-  onSelect?: () => Promise<unknown> | undefined;
+  onSelect?: () => Promise<unknown> | void | undefined;
   selected?: boolean;
   indeterminate?: boolean;
   disabled?: boolean;