diff --git a/.nvmrc b/.nvmrc
index 442c7587..91d5f6ff 100644
--- a/.nvmrc
+++ b/.nvmrc
@@ -1 +1 @@
-22.20.0
+22.18.0
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1e0175b1..70562684 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,9 +1,5 @@
 # Monaco Editor Changelog
 
-## [0.55.1]
-
-- Fixes missing language exports (monaco.json/typescript/...) due to wrong "types" path - [#5123](https://github.com/microsoft/monaco-editor/issues/5123)
-
 ## [0.55.0]
 
 ### Breaking Changes
diff --git a/package.json b/package.json
index f04c68bc..ac2a00cb 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "monaco-editor",
-	"version": "0.55.1",
+	"version": "0.55.0",
 	"vscodeRef": "86f5a62f058e3905f74a9fa65d04b2f3b533408e",
 	"private": true,
 	"description": "A browser based code editor",
@@ -38,7 +38,7 @@
 	"module": "./esm/vs/editor/editor.main.js",
 	"exports": {
 		".": {
-			"types": "./esm/vs/editor/editor.main.d.ts",
+			"types": "./esm/vs/editor/editor.api.d.ts",
 			"import": "./esm/vs/editor/editor.main.js",
 			"require": "./min/vs/editor/editor.main.js"
 		},
diff --git a/website/src/runner/index.ts b/website/src/runner/index.ts
index a489a508..aaedd7e5 100644
--- a/website/src/runner/index.ts
+++ b/website/src/runner/index.ts
@@ -8,12 +8,12 @@ import { IMessageFromRunner, IMessageToRunner, IPreviewState } from "../shared";
 import "./style.scss";
 
 window.addEventListener("message", (event) => {
-	/*const isInSandbox = window.origin === "null";
+	const isInSandbox = window.origin === "null";
 	if (!isInSandbox) {
 		// To prevent someone from using this html file to run arbitrary code in non-sandboxed context
 		console.error("not in sandbox");
 		return;
-	}*/
+	}
 	const e = event.data as IMessageToRunner | { kind: undefined };
 	if (e.kind === "initialize") {
 		initialize(e.state);
diff --git a/website/src/website/pages/playground/Preview.tsx b/website/src/website/pages/playground/Preview.tsx
index 3b5a7112..b2cd8086 100644
--- a/website/src/website/pages/playground/Preview.tsx
+++ b/website/src/website/pages/playground/Preview.tsx
@@ -75,7 +75,7 @@ export class Preview extends React.Component<{
 				<iframe
 					className="full-iframe"
 					key={this.counter}
-					// sandbox="allow-scripts allow-modals"
+					sandbox="allow-scripts allow-modals"
 					frameBorder={0}
 					ref={this.handleIframe}
 					src={`https://isolated-playground.github.io/?jsSrcBase64=${btoa(