Hi Demolition Man,
Do you have Visual Studio 2015 installed? The VS 2015 Redistributes are required for Lightmass building in 4.10. Please update to VS 2015 or install the 2015 Redistribute (located below) and let me know if this fixes the error you are seeing. If not, please post this to the answerhub in the bug reports section (link in signature) so I can assist you more in depth.
Edit: The specific Redistribute needed can be found here if you do not have VS 2015 installed. If you have 2015 installed, do not install this redistribute.