【报Bug】TypeError: Cannot read property 'url' of undefined

<unicloud-db ref="udb" :where="where" v-slot:default="{data, loading, error, options}" collection="overtime-meal,uni-id-users" field="_id,name,depart,pretime,mealtype,state,user_id.nickname,user_id.avatar_file,user_id._id">
我是按多角色留言板的视频开发，我用的是审核角色，数据是获取到了，但是前端显示时报错，请高手帮忙
12:30:34.457 [Vue warn]: Error in render: "TypeError: Cannot read property 'url' of undefined"

found in

---> <UniClouddb> at G:/2020年工作/项目管理/GIS/software/HBuilderX.3.2.12.20211029/HBuilderX/plugins/uniapp-cli/node_modules/@dcloudio/uni-cli-shared/components/unicloud-db.vue
at pages/ucenter/overtime-meal/overtime-meal.vue
12:30:34.458 [system]TypeError: Cannot read property 'url' of undefined
at http://localhost:8080/static/js/pages-ucenter-overtime-meal-overtime-meal.js:203:74
at Proxy.renderList (http://localhost:8080/static/js/chunk-vendors.js:5074:16)
at fn (http://localhost:8080/static/js/pages-ucenter-overtime-meal-overtime-meal.js:129:31)
at normalized (http://localhost:8080/static/js/chunk-vendors.js:5034:37)
at Proxy.renderSlot (http://localhost:8080/static/js/chunk-vendors.js:5131:13)
at Proxy.render (http://localhost:8080/static/js/pages-grid-grid~pages-list-detail~pages-list-list~pages-list-search-search~pages-ucenter-overtime-me~c1cf52c5.js:24:11)
at VueComponent.Vue._render (http://localhost:8080/static/js/chunk-vendors.js:5992:22)
at VueComponent.updateComponent (http://localhost:8080/static/js/chunk-vendors.js:6510:21)
at Watcher.get (http://localhost:8080/static/js/chunk-vendors.js:6929:25)
at Watcher.run (http://localhost:8080/static/js/chunk-vendors.js:7004:22)