Technically, yes. But that error message means you haven't properly configured the sentinel to keep the MN engaged with the network. The sentinel source is located here:

https://github.com/PACCommunity/sentinel

The network doesn't currently enforce sentinel usage but it's a good idea to enable it if you can. Also, you can see your MN status at:

http://monitor.masternodes.work/monitor

best,
break.