Failed to write to 'Untitled1'.

[Deleted user]

I can't save files from editor, on my browser (chrome) pops a massage saying

Failed to write to 'Untitled1'. Failed to retrieve resource from https://ip.internet.internet/vfs/1/9c1vT27S9PWFfV62/workspace/Untitled1 with code 0.

same with

Failed to write to 'state.settings'. Failed to retrieve resource from https://ip.internet.internet/vfs/1/9c2d9tOjrw8ktpwm/ide/.c9/state.settings with code 0.

i am working with two proxys, one at the same system as c9 is running, and one in the internet connecting to the proxy on the c9 system

if i connect to the nginx proxy running on the c9 maschine everything works fine, but not from the other system

here the confs for nginx:
same system as c9:

 location / {
        proxy_pass http://127.0.0.1:8181;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_redirect default;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Client-Verify SUCCESS;
        proxy_read_timeout 1800;
        proxy_connect_timeout 1800;
    }

internet system:

location / {
                       proxy_pass https://ip:7000/;
                       proxy_set_header Host $host;
                       proxy_redirect default;
                       proxy_http_version 1.1;
                       proxy_set_header Upgrade $http_upgrade;
                       proxy_set_header Connection 'upgrade';
                       proxy_set_header X-Client-Verify SUCCESS;
                       proxy_set_header X-Real-IP $remote_addr;
                       proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                       proxy_set_header X-Forwarded-Proto $scheme;
                       proxy_ssl_verify off;

                       proxy_connect_timeout      180s;
                       proxy_send_timeout         180s;
                       proxy_read_timeout         180s;
                       keepalive_timeout  180;
                   }

My browser console shows:
PUT https://ip.internet.internet/vfs/1/9c2d9tOjrw8ktpwm/workspace/.c9/state.settings?access_token=token net::ERR_EMPTY_RESPONSE

Am i doing something wrong?