502 Bad Gateway不是插件的事，是通过server api addone 添加的商品没有生成product_flat.url_key列的值，当product_flat.url_key值为null的时候，就会报错，添加product_flat.url_key字段值解决
我用的是这外插件Fecmall 阿里云图片oss存储fecmall产品图片报错，不用没问题
Http status: 502 Bad Gateway
ajaxOptions: error
thrownError: Bad Gateway
502 Bad Gateway
nginx
以下是head信息
Request URL: http://a.joho.cn/catalog/productinfo/managereditsave
Request Method: POST
Status Code: 502 Bad Gateway
Remote Address: 39.106.99.9:80
Referrer Policy: no-referrer-when-downgrade
Connection: keep-alive
Content-Length: 568
Content-Type: text/html
Date: Fri, 22 May 2020 11:56:51 GMT
Server: nginx
Accept: application/json, text/javascript, */*; q=0.01
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,zh;q=0.9
Connection: keep-alive
Content-Length: 4160
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
Cookie: _ftreturn=0; _fta=1de91ece-c2a0-efe7-0907-f60a3a194fd9; _fta_site_id=9b17f5b4-b96f-46fd-abe6-a579837ccdd9; PHPSESSID=ci8daq52hj3nrud6hp6a010tth; _identity=46f0dab90ae0bb7f695b447727c66dafbf66ae2e623ac581647ddf54f00f29b2a%3A2%3A%7Bi%3A0%3Bs%3A9%3A%22_identity%22%3Bi%3A1%3Bs%3A14%3A%22%5B2%2Cnull%2C86400%5D%22%3B%7D; _csrf=a56f7d1dbd4a72c702d52cb4e144f9507b68b54fb59dee3f0d9b56d3a87e9519a%3A2%3A%7Bi%3A0%3Bs%3A5%3A%22_csrf%22%3Bi%3A1%3Bs%3A32%3A%223VhStUB3TXU-DTWbOJDMKW7c_yTFdZQV%22%3B%7D
Host: a.joho.cn
Origin: http://a.joho.cn
Referer: http://a.joho.cn/
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3865.120 Safari/537.36
X-Requested-With: XMLHttpRequest