With CA Output Management Web Viewer 12.1 and using Windows 10 to do an export, as you click and insert vertical yellow lines, and as you scroll, additional lines may appear. This can happen with wide reports.
MS Windows 10
IE11 version for Windows 10
IE11 has been modified for Windows 10
NOTE: In some cases the exported report does not automatically open in EXCEL. This will most likely have a Microsoft resolution.