Hi there! I understand that when you add a document using Lens, it disappears when you try to access it later. To help you better, could you tell me a bit more about your process? For example:

- Are you saving the document locally on your device or to a cloud service?
- Do you see any error messages when saving or trying to open the document?
- Have you noticed if this happens with all documents or just specific ones?

Meanwhile, here are some general steps that might help resolve the issue:

1. Check Save Location: Ensure that you are saving the document to a location you can easily access, such as a folder you recognize or a cloud account linked to Lens.

2. App Permissions & Storage: Verify that Lens has permission to save to your device storage or cloud service. On Windows, check your account storage and available space, as lack of storage can prevent saving.

3. Sync Issues: If using a cloud service like OneDrive, verify your internet connection is stable and that the app is syncing properly.

4. App Updates: Make sure you're using the latest version of Lens. Sometimes, bugs causing disappeared files are fixed with updates.

5. Access Documents from App: Rather than navigating via file explorer, try accessing your saved documents directly from the Lens app’s "Documents" or "Recent" section to see if they appear there.

6. Restart App & Device: Try closing Lens completely and restarting your browser or computer to refresh the app and system.

If you have already tried these or if Lens saves to a specific cloud (like OneDrive), we can dive deeper—such as checking sync status, account sign-in issues, or app cache.

Could you let me know which of these steps you've tried? That way, I can guide you better!