I have just updated to 2.0.44, I can't get to the Probing tab because it is greyed out. The machine is homed. Everything else seems to be fine.
It would be nice if there was a popup dialog when you click on something that is greyed out to tell you what needs to be done to enable that feature.
I have looked for answers by searching keywords here, and in the Wiki. Can't find any mention of a greyed-out probing tab.