The last two times I have upgraded Windows 10 -- most recently to version 14971 on 11/17/2016 -- my Windows Live Mail became corrupted and inoperative.  After trying several unsuccessful attempts to fix it, I decided to uninstall the complete Windows Live Essentials group.  When I started the uninstall process, I was offered an option to "Fix Windows Live Essentials".  I thought it was worth a try and "voila", it fixed the problem. 

While I like, and use Microsoft Outlook and Windows 10 Mail, I still like many of the Outlook Express holdover features of WLM so having it available is a plus for me.  Yes, I realize WLM is not as secure as the newer MS email clients but I have never had any safety problems with it.

Hope this may be helpful for the few of you out there who still use WLM.