title: Open file URLs in PDFNet / PDFTron WebViewer
body: <p>I'm trying to use PDFNet / PDFTron WebViewer within an Electron based application. The user should be able to select a file from the local filesystem to open. But when passing a file:// URL for <code>initialDoc</code> I always get the error <code>Error retrieving file: file:///Users/mat/Desktop/document-generator/xod/Anchoring/Anchoring.xod?_=-22,. Received return status 0.</code>.</p>
  
  <p>Has anyone an Idea how this could be solved? Copying the file in a folder close to <code>index.html</code> and using a relative URL is not an option, since the PDF documents are quite big.</p>