When trying to export data to Excel, Powerpoint, CSV, through any portlet action, there is no response from the application
A HTML portlet that looks into sessions and cookies and is present on the General Overview page seems to be breaking the Export actions.
Review the portlet and review the code.
Any piece of code that looks into sessions and cookies could be causing the issue.
Place the portlet outside the General page
Reload the page where you want to do the Export by using the F5 button