Ckeditor 5 License: Key

If your project is genuinely GPL-compliant, you can use the 'GPL' key (or the specific open-source key provided by CKSource) to remove the warning. If your project is proprietary and you ignore the warning, you are violating the software license, which carries legal risk.

Message: CKEditorError: license-key-missing

Cause: You are using a premium feature, but no key is set. Fix: Ensure licenseKey is passed in config or window.CKEDITOR_LICENSE_KEY is defined before editor initialization. ckeditor 5 license key

import ClassicEditor from 'ckeditor5';
import 'ckeditor5/ckeditor5.css';
ClassicEditor
.create(document.querySelector('#editor'), 
licenseKey: 'YOUR_LICENSE_KEY_HERE'
)
.catch(error => console.error(error));

import ClassicEditor from '@ckeditor/ckeditor5-editor-classic/src/classiceditor';
import Essentials from '@ckeditor/ckeditor5-essentials/src/essentials';
import Paragraph from '@ckeditor/ckeditor5-paragraph/src/paragraph';
import Bold from '@ckeditor/ckeditor5-basic-styles/src/bold';
// THIS IS WHERE THE LICENSE KEY GOES
ClassicEditor.builtinPlugins = [ Essentials, Paragraph, Bold ];
ClassicEditor
.create( document.querySelector( '#editor' ), 
licenseKey: 'YOUR_CKEDITOR_5_LICENSE_KEY_HERE',  // <-- Insert key
toolbar: [ 'bold', 'undo', 'redo' ]
 )
.then( editor => 
console.log( 'Editor was initialized with a valid license key', editor );
 )
.catch( error => 
console.error( error );
 );
 If your project is genuinely GPL-compliant, you can