this error is around for 4-5 months:
when contacting the traffic API with uppercase BBOX parameter:
https://traffic.arcgis.com/arcgis/rest/services/World/Traffic/MapServer/export?F=image&format=PNG32&...
we receive following error:
Error: Unable to export map
Code: 400
bbox must be specified
when changing bbox to lowercase, then we get back the image with traffic:
https://traffic.arcgis.com/arcgis/rest/services/World/Traffic/MapServer/export?F=image&format=PNG32&...
however, looking at the github project for openlayers at line 46, it requires BBOX uppercase:
https://github.com/openlayers/openlayers/blob/1f085edf037fdf638d6d8b22e1095d7c3a6cafb5/src/ol/source...
can you please check and fix?
thank you
