so far non of my masternodes running with version 2.1.2.1 crashed
some masternodes still running with 2.1.2.0 & just crashed again, so i guess the new version is a nice step ahead for masternodes
What addnodes are you using? I have been syncing for the past 3 hours with none in the masternode darknet.conf files and it's still less than 50% done on the first node.