My revision is 6206. I update new code from SVN server and can not access Visitor overview page.
The error detail is:
Date format must be: YYYY-MM-DD, or 'today' or 'yesterday' or any keyword supported by the strtotime function (see http://php.net/strtotime for more information)
Backtrace:
#0 /home/chuongdu/public_html/tracking/core/ViewDataTable.php(1206): Piwik_Date::factory('last7')
#1 /home/chuongdu/public_html/tracking/core/ViewDataTable/GenerateGraphHTML.php(133): Piwik_ViewDataTable->hasReportBeenPurged()
#2 /home/chuongdu/public_html/tracking/core/ViewDataTable/GenerateGraphHTML.php(97): Piwik_ViewDataTable_GenerateGraphHTML->buildView()
#3 /home/chuongdu/public_html/tracking/core/Controller.php(241): Piwik_ViewDataTable_GenerateGraphHTML->main()
#4 /home/chuongdu/public_html/tracking/plugins/VisitsSummary/Controller.php(78): Piwik_Controller->getLastUnitGraphAcrossPlugins('VisitsSummary', 'getEvolutionGra...', Array, Array, 'This is an over...')
#5 /home/chuongdu/public_html/tracking/plugins/VisitsSummary/Controller.php(23): Piwik_VisitsSummary_Controller->getEvolutionGraph(true, Array)
#6 function: Piwik_VisitsSummary_Controller->index()
#7 /home/chuongdu/public_html/tracking/core/FrontController.php(138): call_user_func_array(Array, Array)
#8 /home/chuongdu/public_html/tracking/index.php(53): Piwik_FrontController->dispatch()
#9 {main}
I update latest revision is 6211 but the bug still happen. You can see it here (it is public)
I think the problem is parameter date=last7.
But this one is work well: http://www.chuongduong.net/tracking/index.php?module=CoreHome&action=index&idSite=1&period=range&date=2012-04-12,2012-04-18#module=VisitsSummary&action=index&idSite=1&period=range&date=2012-04-12,2012-04-18&idDashboard=1