I have configured a new project to scan a site and generate both a sitemap and rss file.
Created a bat file to execute the project...
"C:\Program Files\Microsys\Sitemap Generator 3\Sitemap.exe" -exit -scan -build -uploadall "E:\A1SitemapProjects\ClientSite\A1Client.ini"
When the scheduled bat file is executed and when I manually execute the task I get the following:

"You need to perform a website scan first"
Any ideas as to what I might be missing?

Usually you will get that message if for instance you have loaded an "empty" project (i.e. no website analysis data including URLs etc.)

As you also emailed, we will continue communication there