On Thursday 9/14/2017, Chelsea Rozek (GIS Developer) and the team at Washtenaw County identified a bug that is affecting installs of Geocortex Essentials. The bug is caused by the most recent published Windows Updates. Specifically KB4041085 published on 9/12/2017 is causing blank maps to be produced when exporting or printing from inside the Geocortex Essentials platform. Specifically the update is called "2017-09 Security and Quality Rollup for .NET Framework 3.5, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7 on Windows 8.1 and Server 2012 RN for x64". The update is 71.9 MB in size. At this time, Latitude Geographics is acknowledging the issue and is looking to a workaround. Latitude is also suggesting the update may affect Windows RT 8.1 users. The bug also affects Windows Server 2012 users, however the KB for that install is different. It is titled the same, however, the KB is KB4041084.
Here is a link to the forum post - http://bit.ly/2h4Q62j
Washtenaw County is on Geocortex Essentials 4.8.0 and HTML5 versions 2.8 & 2.9. The City of Ann Arbor is using HTML5 version 2.7.
Chelsea Rozek can be contacted at rozekc@ewashtenaw.org.