There is a way to backup Essentials information, but the backup configuration is set to off by default.
To enable a backup of Essentials, go to (by default):
C:\Program Files (x86)\Latitude Geographics\Geocortex Essentials\Default\REST Elements\Manager\
and edit the web.config file. In there, you will see under the tag -
<add key="NumberOfSiteBackupFiles" value="0" />
Simply change the '0' to "1"