【真机调试】报错 Uncaught TypeError: Cannot read property 'sendBeacon' of undefined

真机调试报错
reportJSException >>>> exception function:createInstanceContext, exception:white screen cause create instanceContext failed,check js stack ->Uncaught TypeError: Cannot read property 'sendBeacon' of undefined
at (app-service.js:18144:227479)
at (app-service.js:18144:286266)
at (app-service.js:18144:286358)
at (app-service.js:18144:37)
at ./node_modules/vconsole/dist/vconsole.min.js (app-service.js:18144:43)
at webpack_require (app-service.js:31:42)
at eval (<anonymous>:9:66)
at ./src/main.js (app-service.js:10064:1)
at webpack_require (app-service.js:31:42)
at __webpack_exec__ (app-service.js:18913:61)

可是代码里没有sendBeacon 这是为什么，求助！！