Ssl_error_rx_record_too_long

I have installed the uboxed docker on a machine of my institute. The installation went smooth but when I try to connect from remote forwarding the port 80 I get the following error on the browser

SSL_ERROR_RX_RECORD_TOO_LONG

Any idea what is the problem?
Thanks a lot
Stefano

Fixed it was a due to the fact that the port 443 was not open on the server.