golang autocert acme / autocert：缺少服务器名称

i use Library autocert in my application for generate ssl certificate, problem is 30% of users have problem with my application, my current code is :

fmt.Println("Starting server on " + this.Params.Bind)
if this.Params.SSL {
    fmt.Println("SSL Enabled")
    m := autocert.Manager{
        Prompt:     autocert.AcceptTOS,
        HostPolicy: autocert.HostWhitelist(this.Params.HostsWhitelist...),
        Cache:      autocert.DirCache(this.Params.CertCache),
    }

    log.Fatal(autotls.RunWithManager(r, &m))
} else {
    r.Run(this.Params.Bind)
}

the errors is :

2018/12/03 12:37:33 http: TLS handshake error from 68.71.48.249:55885: acme/autocert: missing server name
2018/12/03 12:37:33 http: TLS handshake error from 209.213.121.223:38284: acme/autocert: missing server name
2018/12/03 12:37:33 http: TLS handshake error from 209.213.121.223:38283: acme/autocert: missing server name
2018/12/03 12:37:33 http: TLS handshake error from 68.71.48.249:55887: acme/autocert: missing server name
2018/12/03 12:37:33 http: TLS handshake error from 68.71.48.249:55888: acme/autocert: missing server name
2018/12/03 12:37:33 http: TLS handshake error from 209.237.150.145:56842: acme/autocert: missing server name

how i can fix error missing server name ?