To resolve this issue all you have to do is re-select the "Probe' in the materials drop down list to the left of the Auto Button. The Auto Button will then become active.
The Plug-in will gray the Auto button if the Algorithm under Advanced Settings is placed on one of the reflectivity-specific settings. If the Algorithm is placed on Fixed, the Auto button is enabled.
Keywords: LLP settings, auto, llp calibration, llp, laser line probe, scan arm, auto button