Consistent Apache error log understanding

I receive the statement below in my Apache error logs around 15 times a day; the errors reflect the current day. Can anyone help to interpret what needs to be corrected? Clearly, a plugin does not exist, however the question is which plugin folder/file is missing and where can I get it?

File does not exist: /DIRECTORY/web_stats/plugins/MultiSites/templates/plugins, referer: httpwebaddress://stats.rbucky.com/index.php?module=MultiSites&action=index&date=2010-04-29&period=day&idSite=15

System: Ubuntu Server v.8.04

~Mark