Hi @dtkloc,
What steps did you follow when upgrading, was it these ones? It looks like your binary is still from 4.1 so my guess is something in the upgrade process went wrong.
Some other useful information that would help troubleshooting would be, how are you running Mattermost? Is it configured as a service, if so can you share the service configuration file? For example for Ubuntu 14.04 it would look like:
start on runlevel [2345]
stop on runlevel [016]
respawn
limit nofile 50000 50000
chdir /opt/mattermost
setuid mattermost
exec bin/platform