So, you installed Munin in WHM > Manage Plugins, but when it installs, you go to Munin Service Monitor in WHM, and you get a 404?
This fix was provided by Lsupport
mv /usr/local/cpanel/3rdparty/bin/rrdtool /usr/local/cpanel/3rdparty/bin/rrdtool.bak /scripts/rrdtoolinstall --force
Run the two lines above in SSH as root, then go into WHM and uninstall and reinstall Munin in Plugin Manager, and it should start working.
