Not wanting to loose settings for my 2.6 2.7 and 3.1 I modified gutenbar's approach renaming roaming/cura then after starting 3.2 and letting it create the cura and cura/3.2 folders I copied the 2.6 2.7 and 3.1 folders from the renamed cura folder and they are all peacefully coexisting. THANK YOU gutenbar you are wunderbar.
I am having the same problem BUT the folder he was told to delete in APPDATA doesn't exist on my machine. I have appdata/local/cura in which are I have versions 15. 2.6, 2.7 and 3.1 installed and working but when trying to launch 3.2 I get the same ' out of range NoneType' error shown in this original post.