On request index.php?forceView=1&viewDataTable=sparklines&module=Goals&action=get&idGoal=10&allow_multiple=0&only_summary=1&idSite=2&period=day&date=2020-08-17,2020-08-23&segment=&showtitle=1&random=8740

following error happened because a data table map was returned instead of a regular data table. And in this case the first row is a dataTable and not a row.

Error: {"message":"Call to undefined method Piwik\DataTable\Simple::getComparisons()","file":"/plugins/CoreVisualizations/Visualizations/Sparklines.php","line":125,"request_id":"12345","backtrace":" on /plugins/CoreVisualizations/Visualizations/Sparklines.php(125)\n#0 /plugins/CoreVisualizations/Visualizations/Sparklines.php(94): Piwik\Plugins\CoreVisualizations\Visualizations\Sparklines->fetchConfiguredSparklines()\n#1 /core/Plugin/Report.php(320): Piwik\Plugins\CoreVisualizations\Visualizations\Sparklines->render()\n#2 /plugins/CoreHome/Controller.php(58): Piwik\Plugin\Report->render()\n#3 [internal function]: Piwik\Plugins\CoreHome\Controller->renderReportWidget(Object(Piwik\Plugins\Goals\Reports\Get))\n#4 /core/FrontController.php(590): call_user_func_array(Array, Array)\n#5 /core/FrontController.php(165): Piwik\FrontController->doDispatch('Goals', 'get', Array)\n#6 /core/dispatch.php(34): Piwik\FrontController->dispatch()\n#7 /index.php(27): require_once('/c...')\n#8 {main}"}