When opening Plato you are prompted to browse to the Esko ArtiosCAD 12.0en.msi file.
When opening Plato you receive the following message:
The feature you are trying to use is on a network resource that is unavailable.
Click OK to try again or enter an alternate path to a folder containing the installation package 'Esko ArtiosCAD 12.0en.msi' in the box given below.
The problem is that the CAD-X for Plato, has not been installed properly. To correct this, it needs to be reinstalled from the Interactive Applications installer.