Why can’t I run my servers as non-root?
In all likelihood, you have at some point run the servers as root, which has allowed the superuser to create new files that are then only accessible/modifiable as root. Since your non-root users (a.k.a. unprivileged users) can then not properly access/modify the minecraft files, it naturally will error out and crash before starting.
You will need to change ownership (chown) of these files from their current owner (root) to another user.
root@mineos ~# chown -R mc:mc /var/games/minecraft/servers/myserver
root@mineos ~# chown -R mc:mc /var/games/minecraft/archive/myserver
root@mineos ~# chown -R mc:mc /var/games/minecraft/backup/myserver
See this post.