-f here gets passed to limit, which is supposed to set a filesize limit. I'm not sure why it was here, but it didn't work for me.

Installation.md

@@ -93,7 +93,7 @@ load_rc_config $name
 
 procname="/usr/local/bin/mono"
 command="/usr/sbin/daemon"
-command_args="-f ${procname} /usr/local/share/Radarr/Radarr.exe --data=${radarr_data_dir}"
+command_args="${procname} /usr/local/share/Radarr/Radarr.exe --data=${radarr_data_dir}"
 
 start_precmd="export XDG_CONFIG_HOME=${radarr_data_dir}"