Hello,
the error code 0x80080005 comes from WebView2, the Microsoft component the PDF24 Toolbox uses to display its window: WebView2 could not be started. Version 11.18.0 is quite old, so please first install the current version: https://tools.pdf24.org/en/creator
If the error still occurs, open the PDF24 settings (for example in PDF24 Creator under Tools > Preferences), go to the page "Components" and set WebView2 to "Installed system version". This uses the Microsoft Edge WebView2 Runtime installed in Windows, which you can get from Microsoft if it is missing: https://developer.microsoft.com/microsoft-edge/webview2/
With the next version, PDF24 switches to the WebView2 installed in Windows automatically if the bundled one does not start.