Version

3.0.5

Reproduction link

https://codepen.io/bastarder/pen/QWKBjoN

Steps to reproduce

https://codepen.io/bastarder/pen/QWKBjoN in this demo, everything is ok only your should do is delete {{ row.checkList.length }} in template after you delete this line, will throw error, why

What is expected?

no error

What is actually happening?

throw error

i think it is a vue bug, can you help me to find out why?

Please submit this issue to element-plus first, I tried to read its source code, but it is really huge. I tried to use the following simple component instead of el-column, and it could not be reproduced. I think you should give a clean reproduction. If this issue only occurs in a specific environment (e.g. element-plus) then please submit an issue there first.

const ElColumn = defineComponent({
  data() {
    return {
      row: { checkList: [] }
    }
  },
  render() {
    return this.$slots.default && this.$slots.default({ row: this.row })
  }
})