Probable Resolution #1:
The spatial reference system (SRS) must be properly set on the LAS Layer as that is where the Reproject PCT will be looking for the information. For example, if the original LAS data uses NAVD88, but doesn’t specify the specific geoid model in a way that LP360/True View EVO knows how to interpret, then you will have to manually set it on the LAS Layer in order to be able to run the PCT.
Probable Resolution #2:
If using a vertical datum or geoid version not currently supported by LP360 or True View EVO please contact support for further assistance.