When a user tries to save a report using OM Web viewer the file is saved as empty txt file. If the user clicks on browse on that report it shows the entire report. The only issue is with the save of the file.
Improper permissions in Windows System Environment Variable, Temp
Zero byte saved files are indicative of lost permissions to the Temp directory on the Windows Server where the Web Viewer runs. When saving a file, Web Viewer writes the file to a temporary file on the server first. When that write is complete and verified, the file is then pushed to the user's machine. In order for this process to work correctly, IIS User must have permission to write to the System Environment Temp folder on the server - usually defined to be C:\Windows\Temp.
To test this, give "everyone" full control to the Temp folder.