使用ecahrts的官方实例的echarts.js:11954 Uncaught Error: series.type should be specified. at Function.entity.getClass (echarts.js:11954)

echarts.js:11954 Uncaught Error: series.type should be specified.
    at Function.entity.getClass (echarts.js:11954)
    at ExtendedClass.<anonymous> (echarts.js:20753)
    at Array.forEach (<anonymous>)
    at each$1 (echarts.js:528)
    at ExtendedClass.visitComponent (echarts.js:20736)
    at Function.entity.topologicalTravel (echarts.js:17832)
    at ExtendedClass.mergeOption (echarts.js:20706)
    at ExtendedClass.initBase (echarts.js:21237)
    at ExtendedClass.resetOption (echarts.js:20648)
    at ExtendedClass.setOption (echarts.js:20630)