In both LP360 for ArcGIS and LP360 (32-bit) when you add LAS files no “LAS Layer” gets added to the Table of Contents (TOC). The program appears to do nothing and you get control back immediately. There are no error messages, no indication of pyramids being built, and no “LAS Layer” generated.
There is a failure in Microsoft’s COM library call. Suspect that something wrong with the Windows installation on the machine. Perhaps some other software is also failing. Format and reinstall the software on the machine to correct this issue.