Solution 1:
You should never run munin-cron with 'root' user.
Try running this command:
chown -R munin:munin /var/www/munin
After this try running "munin-cron" back from the "munin" user.
You should never run munin-cron with 'root' user.
Try running this command:
chown -R munin:munin /var/www/munin
After this try running "munin-cron" back from the "munin" user.