The renderer accepts only a Piwik_DataTable or an array of DataTable (Piwik_DataTable_Array) object.
Backtrace:#0 /home/uploader/piwik/core/ViewDataTable/HtmlTable.php(158): Piwik_DataTable_Renderer->setTable(false) #1 /home/uploader/piwik/core/ViewDataTable/HtmlTable.php(119): Piwik_ViewDataTable_HtmlTable->getPHPArrayFromDataTable() #2 /home/uploader/piwik/core/ViewDataTable/HtmlTable.php(89): Piwik_ViewDataTable_HtmlTable->buildView() #3 /home/uploader/piwik/core/Controller.php(152): Piwik_ViewDataTable_HtmlTable->main() #4 /home/uploader/piwik/plugins/MultiSites/Controller.php(240): Piwik_Controller->renderView(Object(Piwik_ViewDataTable_HtmlTable), false) #5 [internal function]: Piwik_MultiSites_Controller->getEvolutionGraph() #6 /home/uploader/piwik/core/FrontController.php(138): call_user_func_array(Array, Array) #7 /home/uploader/piwik/index.php(53): Piwik_FrontController->dispatch() #8 {main}