@@ -2,6 +2,7 @@
 // Licensed under the MIT license.
 
 import * as vscode from "vscode";
+import { leetCodeTreeDataProvider } from "../explorer/LeetCodeTreeDataProvider";
 import { leetCodeExecutor } from "../leetCodeExecutor";
 import { leetCodeManager } from "../leetCodeManager";
 import { DialogType, promptForOpenOutputChannel, promptForSignIn } from "../utils/uiUtils";
@@ -24,5 +25,8 @@ export async function submitSolution(uri?: vscode.Uri): Promise<void> {
 leetCodeSubmissionProvider.show(result);
 } catch (error) {
 await promptForOpenOutputChannel("Failed to submit the solution. Please open the output channel for details.", DialogType.error);
+return;
 }
+
+leetCodeTreeDataProvider.refresh();
 }

@@ -11,11 +11,15 @@ import { LeetCodeNode } from "./LeetCodeNode";
 
 export class LeetCodeTreeDataProvider implements vscode.TreeDataProvider<LeetCodeNode> {
 
-private onDidChangeTreeDataEvent: vscode.EventEmitter<any> = new vscode.EventEmitter<any>();
+private context: vscode.ExtensionContext;
+
+private onDidChangeTreeDataEvent: vscode.EventEmitter<LeetCodeNode | undefined | null> = new vscode.EventEmitter<LeetCodeNode | undefined | null>();
 // tslint:disable-next-line:member-ordering
 public readonly onDidChangeTreeData: vscode.Event<any> = this.onDidChangeTreeDataEvent.event;
 
-constructor(private context: vscode.ExtensionContext) { }
+public initialize(context: vscode.ExtensionContext): void {
+this.context = context;
+}
 
 public async refresh(): Promise<void> {
 await explorerNodeManager.refreshCache();
@@ -26,7 +30,6 @@ export class LeetCodeTreeDataProvider implements vscode.TreeDataProvider<LeetCod
 if (element.id === "notSignIn") {
 return {
 label: element.name,
-id: element.id,
 collapsibleState: vscode.TreeItemCollapsibleState.None,
 command: {
 command: "leetcode.signin",
@@ -35,11 +38,9 @@ export class LeetCodeTreeDataProvider implements vscode.TreeDataProvider<LeetCod
 };
 }
 
-const idPrefix: number = Date.now();
 return {
 label: element.isProblem ? `[${element.id}] ${element.name}` : element.name,
 tooltip: this.getSubCategoryTooltip(element),
-id: `${idPrefix}.${element.id}`,
 collapsibleState: element.isProblem ? vscode.TreeItemCollapsibleState.None : vscode.TreeItemCollapsibleState.Collapsed,
 contextValue: element.isProblem ? "problem" : element.id.toLowerCase(),
 iconPath: this.parseIconPathFromProblemState(element),
@@ -128,3 +129,5 @@ export class LeetCodeTreeDataProvider implements vscode.TreeDataProvider<LeetCod
 ].join(os.EOL);
 }
 }
+
+export const leetCodeTreeDataProvider: LeetCodeTreeDataProvider = new LeetCodeTreeDataProvider();

@@ -12,7 +12,7 @@ import * as submit from "./commands/submit";
 import * as test from "./commands/test";
 import { explorerNodeManager } from "./explorer/explorerNodeManager";
 import { LeetCodeNode } from "./explorer/LeetCodeNode";
-import { LeetCodeTreeDataProvider } from "./explorer/LeetCodeTreeDataProvider";
+import { leetCodeTreeDataProvider } from "./explorer/LeetCodeTreeDataProvider";
 import { leetCodeChannel } from "./leetCodeChannel";
 import { leetCodeExecutor } from "./leetCodeExecutor";
 import { leetCodeManager } from "./leetCodeManager";
@@ -34,7 +34,7 @@ export async function activate(context: vscode.ExtensionContext): Promise<void>
 leetCodeTreeDataProvider.refresh();
 });
 
-const leetCodeTreeDataProvider: LeetCodeTreeDataProvider = new LeetCodeTreeDataProvider(context);
+leetCodeTreeDataProvider.initialize(context);
 
 context.subscriptions.push(
 leetCodeStatusBarController,