microsoft/monaco-editor · error · Error

monaco is not loaded yet

Error message

monaco is not loaded yet

What it means

Thrown by getLoadedMonaco() in the website's monaco-loader when the module-level `monaco` binding is still undefined. The loader exposes loadMonaco()/waitForLoadedMonaco() as the async path that actually imports/configures Monaco, and getLoadedMonaco() as a synchronous accessor usable only after loading completes. Calling it before the load promise resolves violates the contract and throws, signalling a race where consumer code ran too early.

Source

Thrown at website/src/monaco-loader.ts:8

/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/

export function getLoadedMonaco(): typeof monaco {
	if (!monaco) {
		throw new Error("monaco is not loaded yet");
	}
	return monaco;
}

export function getMonaco(): typeof monaco | undefined {
	return (window as any).monaco;
}

export type IAMDMonacoSetup = {
	loaderUrl: string;
	loaderConfigPaths: Record<string, string>;
	codiconUrl: string;
	monacoTypesUrl: string | undefined;
	language?: string;
};

export type IESMMonacoSetup = {
	esmUrl: string;

View on GitHub (pinned to ca1b42dc89)

Solutions

1. Await loadMonaco(setup) (or waitForLoadedMonaco()) before calling getLoadedMonaco().
2. Gate any code that needs Monaco behind the resolved load promise (e.g. `await waitForLoadedMonaco(); const m = getLoadedMonaco();`).
3. If you only need the value optionally, use getMonaco() which returns undefined instead of throwing.
4. Ensure loadMonaco() is invoked exactly once at app boot, before any consumer tries to read Monaco.

Example fix

// before
const monaco = getLoadedMonaco(); // throws if not yet loaded
monaco.editor.create(...);
// after
await loadMonaco(setup);
const monaco = getLoadedMonaco();
monaco.editor.create(...);

// ensure load has completed before any synchronous read
await loadMonaco(setup); // or await waitForLoadedMonaco();
if (!getMonaco()) {
  throw new Error('Monaco failed to load');
}
const monaco = getLoadedMonaco(); // now safe

function isMonacoLoaded(): boolean {
  return typeof (window as any).monaco !== 'undefined';
}

When it happens

Trigger: Calling getLoadedMonaco() synchronously at module init, in a render, or in an event handler before loadMonaco() has been awaited; assuming Monaco is available because the script tag was added but the AMD require callback hasn't fired yet.

Common situations: A React/Vue component calls getLoadedMonaco() in its setup before the parent triggered loadMonaco(); test code that mounts the playground without booting the loader; refactoring that removed or reordered the loadMonaco() call.

Related errors

• already initialized
• already initialized
• one parameter must be defined
• You must define a function MonacoEnvironment.getWorkerUrl or
• Invalid language id: ${this._languageId}

AI-assisted analysis of microsoft/monaco-editor@ca1b42dc89 (2026-08-13). Data as JSON: /api/errors/46d3f567ffd5d398. Report an issue: GitHub.