When Lucity is installed it checks to see which version of ArcGIS is installed on the computer. If they are installed out of order Lucity will not see ArcGIS or be looking for the wrong version. This will cause problems with the Lucity > GIS integration. If ArcGIS is installed after Lucity, the Lucity Desktop installation MUST be repaired to recognize the version of ArcGIS installed on the machine.
How To Repair Lucity