No Content shown when Line Chart (but workaround with smoothed line chart)

I found a strange bug(?) in Chartboot. When I include the following chart the entire post is not shown (just saying ‘No Content’):

[chartboot version= '2.3' code= '7E83' border= '1' width= '625' height= '325' attribution= '1' jsondesc= '{"containerId":"visualization7E83","dataTable":{"cols":^{"id":"","label":"Year","pattern":"","type":"string"},{"id":"","label":"Africa","pattern":"","type":"number"},{"id":"","label":"Asia","pattern":"","type":"number"},{"id":"","label":"Europe","pattern":"","type":"number"},{"id":"","label":"Latin America and the Caribbean","pattern":"","type":"number"},{"id":"","label":"Northern America","pattern":"","type":"number"},{"id":"","label":"Oceania","pattern":"","type":"number"}|,"rows":^{"c":^{"v":"1950","f":null},{"v":0.229895,"f":null},{"v":1.403389,"f":null},{"v":0.547287,"f":null},{"v":0.167368,"f":null},{"v":0.171615,"f":null},{"v":0.012675,"f":null}|},{"c":^{"v":"1955","f":null},{"v":0.255521,"f":null},{"v":1.549293,"f":null},{"v":0.575236,"f":null},{"v":0.191707,"f":null},{"v":0.18696,"f":null},{"v":0.014165,"f":null}|}|,"p":null},"options":{"legend":"right","curveType":"","vAxes":^{"title":null,"minValue":null,"maxValue":null,"viewWindow":{"max":null,"min":null},"useFormatFromData":true},{"viewWindow":{"max":null,"min":null},"minValue":null,"maxValue":null,"useFormatFromData":true}|,"animation":{"duration":500},"booleanRole":"certainty","lineWidth":2,"hAxis":{"minValue":null,"maxValue":null,"viewWindow":null,"viewWindowMode":null,"useFormatFromData":true}},"state":{},"view":{},"isDefaultVisualization":true,"chartType":"LineChart"}' ]

Yet when I put the same chart and choose smoothed line chart as the chart type it works fine. (I have changed to Twenty Ten and switched off every plugin I am using and still encounter this problem.)

https://www.ads-software.com/extend/plugins/chartboot-for-wordpress/