net::ERR_EMPTY_RESPONSE

GET ET https://getaway.onlyeduhi.cn/tcrm/work/teacher/getCourseRecordList?subject=&startDate=&endDate=&courseType= net net::ERR_EMPTY_RESPONSE

与页面debug一直报错，提示

createError.js?9741:15 Uncaught (in promise) Error: Network Error
    at createError (createError.js?9741:15)
    at XMLHttpRequest.handleError (xhr.js?a790:87)

与

Access to XMLHttpRequest at 't 'https://getaway.onlyeduhi.cn/tcrm/work/teacher/getCourseRecordList?subject=&startDate=&endDate=&courseType=' fro from origin 'n 'http://172.16.10.10:8088' ha' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.

一直认为是页面或后端跨域问题，后端跨域也有设置，检查了前后端确实没找到跨域问题，郁闷...

后来竟然发现是服务端返回的json格式，页面没有按返回格式解析，导致解析错误，控制台就出现了以上提示，有点莫名其妙，不过确实是这个问题；