After downloading NumXL setup (installer) program of website and attempt to launch the installer, an NSIS Error message pops up: "Installer integrity check failed, Common causes are incomplete download and damaged media".
Please, check the downloaded file size. If the size is suspiciously small ( less than 1024k), then you have an incomplete download. Otherwise, contact our support line
For incomplete download, please try again, but this time, right click on the download link, a popup menu is shown, choose "Save Link as" option and select a folder on you local disk (e.g. C:\temp).