A plot has an illegal scale. This could for example be that you are trying to use text auto scaling to draw a line plot with only one point or that the plot area is too small. It could also be that no input data value is numeric (perhaps only '-' or 'x')
/images/airbnb-&-vrbo-analytics-listings-per-month-in-antwerp-ny-39684.png
#0 /var/www/prod/bnbseo/app/resources/Tools/jpgraph/src/jpgraph.php(4405): App\Tools\jpgraph\src\JpGraphError::RaiseL(25068)
#1 /var/www/prod/bnbseo/app/resources/Tools/jpgraph/src/jpgraph.php(4626): App\Tools\jpgraph\src\LinearTicks->_doAutoTickPos(Object(App\Tools\jpgraph\src\LinearScale))
#2 /var/www/prod/bnbseo/app/resources/Tools/jpgraph/src/jpgraph.php(4002): App\Tools\jpgraph\src\LinearTicks->Stroke(Object(App\Tools\jpgraph\src\RotImage), Object(App\Tools\jpgraph\src\LinearScale), 300)
#3 /var/www/prod/bnbseo/app/resources/Tools/jpgraph/src/jpgraph.php(2461): App\Tools\jpgraph\src\Axis->Stroke(Object(App\Tools\jpgraph\src\LinearScale), false)
#4 /var/www/prod/bnbseo/app/resources/Tools/jpgraph/src/jpgraph.php(2122): App\Tools\jpgraph\src\Graph->StrokeAxis(false)
#5 /var/www/prod/bnbseo/app/controllers/IndexController.php(372): App\Tools\jpgraph\src\Graph->Stroke()
#6 [internal function]: Controller\IndexController->renderchartAction('airbnb-&-vrbo-a...')
#7 [internal function]: Phalcon\Dispatcher->callActionMethod(Object(Controller\IndexController), 'renderchartActi...', Array)
#8 [internal function]: Phalcon\Dispatcher->dispatch()
#9 /var/www/prod/bnbseo/public/index.php(249): Phalcon\Mvc\Application->handle('/images/airbnb-...')
#10 {main}