I had the same problem and there are two solutions for it to work
1 - with winreducer : don't remove windows store and any related services
2 - you can use another software called MSMG toolkit "only" to remove windows store, then you can use winreducer to do the rest
somehow winreducer messes with MS Account login when you remove Windows Store with it and I don't know why.
Perhaps it's a bug and they fix it later.
so if you are ok with windows store, just don't remove it.
if you also want the store removed, remove it with MSMG toolkit and then do the rest with winreducer.