I did a couple of installs with 2017.01.01 and I noticed that the Libre Office spell check was inoperative. At that time, I submitted a post to the forum on the subject.
I just used the latest ISO to do a fresh install and I noticed that this problem is still unresolved. It seems that even though Libre Office is provided with both the English dictionary and the Hunspel spellchecker by default, for some reason, Libre Office is not able to find Hunsell. My workaround was to download the English dictionary directly from the Libre Office site and then install it. Once this action is performed, Libre Office magically finds Hunspell and it now appears in the “Available writing modules” box, located at the top of the “Tools/Options/Language Settings/Writing Aids” tab.
This may not be the correct, most elegant solution, but it is effective.