Excel/Powerpoint UI issues

Hello, we are implementing your ASP.NET Webforms solution in our project, but we had some issues:


  • Cutting large sheets into multiple sheets;


  • Opening a powerpoint, has a weird behaviour with special characters, eg “é”, “ó” etc;

  • Powerpoint navigation sometimes goes to wrong slide and pagination gets wrong;

  • When resizing the window (minimize, maximize), we lose the thumbnail button.

We did this tests also on your GitHub code without changing nothing (only added license) and the issues persists.
We also repeated this tests on your browser viewer, but there worked without problems.

What are the differences between the sample code and the viewer you have online? Can we have that viewer frontend source code?

app_viewer.jpg (261.1 KB)

browser_viewer.png (286.6 KB)

Kind regards,


I’m sorry for the delayed response. To render a worksheet to a single page please add the following code to Global.asax.cs file

  var uiConfig = UIConfig.Instance
  var viewerConfig = ViewerConfig.Instance
  // Add this code
  viewerConfig.HtmlViewOptions.SpreadsheetOptions = 

The issues with PowerPoint can’t be fixed right a way with the UI used in WebForms Demo and other our demo projects.

These are two distinct projects. By the end of this month we’re planning to replace UI in our demo projects with the UI from Online Viewer and publish the code to GitHub and package that is based on it to NPM.