You may face following errors while installing ORCHARD CMS from WebsitePanel's web application gallery. In such case, you can skip the one click installation and install ORCHARD CMS Manually. Check out our article how to install Orchard CMS manually.
GeneralError - ProcessingFeedXMLError:BUG:No feeds in cache.; at WebsitePanel.Providers.Web.WPIWebApplicationGallery.WPIApplicationGallery.GetWpiHelper(Int32 UserId) at WebsitePanel.Providers.Web.IIs60.GetGalleryApplication(Int32 UserId, String id)
ApplicationInstallationError
Orchard CMS installing error - Failure: Downloaded file failed signature verification and may have been tampered with