I am also getting this issue after migrating from Kentico 7.0 to Kentico 8.0. All of the reports in the Web Analytics section of the site are broken. Here is one example error:
Event ID:
469475
Event type:
Error
Event time:
11/26/2014 9:42:56 AM
Source:
Report graph
Event code:
E
Description:
Message: Report graph 'pageviews.weekreport.graph' not found.
Exception type: System.Exception
Event URL:
/CMSModules/WebAnalytics/Tools/Dashboard.aspx?dashboardName=WebAnalytics&templateName=WebAnalyticsDashboard&hash=b711a717546a545d331a8cec4f0918c26ce472ff645408a4ffc635ba371e4f58
User agent:
Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; rv:11.0) like Gecko
This is happening for all of the analytics reports.