# Pdfjs express viewer not loading the document - Invalid key **URL:** \ **Category:** Technical Support\ **Created:** [May 20, 2022, 6:22am UTC](https://pdfjs.community/t/pdfjs-express-viewer-not-loading-the-document-invalid-key/1694 "2022-05-20T06:22:41Z")\ **Posts on this page:** 1\ **Showing post:** 3
**Author:** ![system](https://canada1.discourse-cdn.com/flex031/uploads/pdfjscommunity/original/1X/ffbcd25c7d423db8d5acd5db201c272f4db306dd.png) [@system](https://pdfjs.community/u/system)\ **Post date:** [May 20, 2022, 6:22am UTC](https://pdfjs.community/t/pdfjs-express-viewer-not-loading-the-document-invalid-key/1694/3 "2022-05-20T06:22:49Z")
**Hello, I’m Ron, an automated tech support bot 🤖** While you wait for one of our customer support representatives to get back to you, please check out some of these documentation pages: Guides: - [Adding your license key](https://pdfjs.express/documentation/get-started-viewer/add-license-key) - [Integrating PDF.js Express Viewer with NPM](https://pdfjs.express/documentation/get-started-viewer/npm) - [Integrating PDF.js Express Viewer into an existing Angular project - Prerequisites](https://pdfjs.express/documentation/get-started-viewer/angular/exist-project#prerequisites) APIs: - [PDF.js Express Utilities](https://pdfjs.express/api/utils/index.html#__anchor) - [Core - onDateSelected(date)](https://pdfjs.express/api/Core.html#.onDateSelected__anchor) - [Adding a download button](https://pdfjs.express/api/utils/tutorial-Adding%20a%20download%20button.html#__anchor) Forums: - [Pdfjs.express watermark despite licence key & correct domain](https://pdfjs.community/t/pdfjs-express-watermark-despite-licence-key-correct-domain/1592/1) - [Watermark issue](https://pdfjs.community/t/watermark-issue/1586/1) - [PDF viewer is not recognizing my license key](https://pdfjs.community/t/pdf-viewer-is-not-recognizing-my-license-key/1353/1) --- _[View the full topic](https://pdfjs.community/t/pdfjs-express-viewer-not-loading-the-document-invalid-key/1694)._