Hi, I am trying to get the audit log report (site actions-site settings-audit log reports) When I click the link's content viewing, content modification or any link after about 3-4 minutes, SharePoint throws an unknown error message. Can you please help me why the reports are not generating.

If you are getting this error "Report contains no data", then most probable reason is you have not set audit settings for site collection. Set audit from Home > Site Settings > Site collection audit settingsw: http://www.worldofsharepoint.com | t: @sharesandip

Hi Sandip, Thanks for fast response, here the error message is unknown error, the site collection audit settings are already selected. any other clue

Set your ULS logging on verbose and reproduce the issue. Also, it would be good to see if there are any errors in your application logs. Although SharePoint says it is an "Unknown Error" It may register with an error code in one of the log files. If you can get ahold of this information, it would be very helpful to help you diagnose.