On Windows, when you try to update Exploratory from version 4.1 to 4.2, you might get an error that says it cannot find installed R. And even after you select your R installation folder on directory selection Dialog, it still says Invalid location. (like below screen shot)
This is because selected R version (in this case R 3.4.1) is not compatible with Exploratory version 4.2
How to fix it
If you got this error and want to use existing R on your computer rather than installing R from Exploratory, you might want to try download R 3.4.3 manually from here and install it. Once R installation is done. Please double click Exploratory.exe and resume Exploratory v4.2 update.