Troubleshooting: Reports that are saved as Excel or Word files are blank
While you are viewing a report in Print Preview in the Microsoft Dynamics NAV Web client, you save the report as a Microsoft Excel or Microsoft Word file. When you open the saved file, it is empty.
Resolution
On the computer that is running Microsoft Dynamics NAV Web Server components, you must give users read, write, and modify permission to the Temp folder of the user account that is used by the web site of the Microsoft Dynamics NAV Web client. The default user account is ApplicationPoolIdentity and the folder is C:\Users\Web Client Application Pool\AppData\Local\Temp\.
See Also
Troubleshooting the Microsoft Dynamics NAV Web Client Installation