The main reason the platform is not found is when the versions of the platform and InRoads is not compatible.
For example: InRoads is not compatible with AutoCAD on a 64 bit OS. So, InRoads would not find a CAD platform in this situation. Another example is if MicroStation XM was installed with InRoads V8i SELECTseries 2. These two products are not compatible with each other and the CAD platform would not be found.