Issue with ssl

hi everyone

I am new biginner for the hassio, everything is ok except ssl for hassio, currently hassio is running on an unraid, i set up a ngnix proxy server for encrypt and revese proxy. The question is when I am using lets encrypt ( hassio addon) I always get errors

Detail: Invalid response from

404 Not
Found\r\n<body bgcolor=“white”>\r\n

Not Found


How can I fixed it