At least on 4 PCs I am experiencing this same problem - They are not in the Inventory of all devices and therefore they do not have all of the Portal Manager Icons. Portal Manager is blank.
Already tried uninstallwinclient.exe /UI /FORCECLEAN /REBOOT and reinstalled agent a number of times and still not showing in inventory.
Also I already increased the Max Scan File Size to 15000000.
hen running Inventory Scan, it will start, and after a few progress bars, it just disappears.
When running Security scan it goes all the way and at the very end it says failed - "Core could not process data"