SQL Server Management Studio 2016 (Release 16) keeps on crashing

You are not alone. See more details here.

Posted by Microsoft:

Turns out there's a thread leak in a utility class. The number of threads leaked will be proportional to the number of registered servers you have, among other things. A fix is coming in the next release

Removing servers from Registered Servers will stop SSMS from crashing. If you can afford to do so, I'd recommend it till Microsoft releases a fix.