we used lightstreamer 4.0 and now upgrading to 5.1, we now use the demo license for testing.

I first rebuilt the adapter, .net client using new .net SDKs.

when the .net client try to connect to lightstreamer server, we got the exception on the client side:

connection error: Lightstreamer.DotNet.Client.PushServerException: Incorrect answer: <!--
at Lightstreamer.DotNet.Client.ExtConnectionListener. WaitStreamingTimeoutAnswer()
at Lightstreamer.DotNet.Client.LSClient.OpenConnectio n(ConnectionInfo info, IConnectionListener listener)
at LightstreamClient.ConnectHelper(Int32 ph)

while on the lightstreamer server log, we got

19-Feb-13 14:09:44,198|DEBUG|LightstreamerLogger.connections |r Lightstreamer HTTP Server|Socket accept on 127.0.0.1:7159.
19-Feb-13 14:09:44,198|INFO |LightstreamerLogger.connections |SERVER POOLED THREAD 1 |Accepted HTTP connection on "Lightstreamer HTTP Server" from 127.0.0.1:7159
19-Feb-13 14:09:44,198|DEBUG|htstreamerLogger.connections.ht tp|SERVER POOLED THREAD 1 |Writing pre-response:
HTTP/1.1 100 continue

on "Lightstreamer HTTP Server" from 127.0.0.1:7159
19-Feb-13 14:09:44,199|DEBUG|htstreamerLogger.connections.ht tp|SERVER POOLED THREAD 7 |Parsing request:
POST /lightstreamer/create_session.txt HTTP/1.1
Content-Type: application/x-www-form-urlencoded
Host: ls.localhost:8080
Cache-Control: no-store,no-cache
Pragma: no-cache
Content-Length: 132
Expect: 100-continue

LS_user=*****&LS_adapter_set=***&LS_content_length =50000000&LS_report_info=true on "Lightstreamer HTTP Server" from 127.0.0.1:7159
19-Feb-13 14:09:44,200|DEBUG|LightstreamerLogger.requests |SERVER POOLED THREAD 7 |evaluating KEEPALIVE - no result configured
19-Feb-13 14:09:44,200|DEBUG|LightstreamerLogger.connections |SERVER POOLED THREAD 7 |Processing push request:
/lightstreamer/create_session.txt on "Lightstreamer HTTP Server" from 127.0.0.1:7159
19-Feb-13 14:09:44,200|INFO |htstreamerLogger.connections.http|SERVER POOLED THREAD 7 |Sending error page upon request:
POST /lightstreamer/create_session.txt HTTP/1.1
Content-Type: application/x-www-form-urlencoded
Host: ls.localhost:8080
Cache-Control: no-store,no-cache
Pragma: no-cache
Content-Length: 132
Expect: 100-continue

LS_user=***&LS_adapter_set=***&LS_content_length=5 0000000&LS_report_info=true on "Lightstreamer HTTP Server" from 127.0.0.1:7159
19-Feb-13 14:09:44,200|DEBUG|LightstreamerLogger.requests |SERVER POOLED THREAD 7 |evaluating use_http_11 - result from base rule: true
19-Feb-13 14:09:44,200|DEBUG|LightstreamerLogger.requests |SERVER POOLED THREAD 7 |evaluating use_http_11 - result from base rule: true
19-Feb-13 14:09:44,200|DEBUG|htstreamerLogger.connections.ht tp|SERVER POOLED THREAD 7 |Writing response:
HTTP/1.1 200 OK
Server: Lightstreamer/5.1.1 build 1623.2 (Lightstreamer Push Server - www.lightstreamer.com) Allegro edition
Last-Modified: Tue, 19 Feb 2013 18:35:43 GMT
Content-Type: text/html; charset=iso-8859-1
Date: Tue, 19 Feb 2013 19:09:44 GMT
Content-Length: 1179
Connection: close

<!--
This page is sent back to a client when an invalid URI is submitted.

This page can be freely edited. Any images can be put in the "pages"
directory and served through the internal Web Server (see
lightstreamer_conf.xml). The only exception is the
"/lightstreamer/Lightstreamer_0308x0080.png" image, which is embedded
in Lightstreamer Server and does not need the activation of the internal
Web Server.
-->

<html>

<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<title>Lightstreamer Server</title>
</head>

<body link="#0066FF">

<p align="center"><a href="http://www.lightstreamer.com"><img border="0" src="/lightstreamer/Lightstreamer_0308x0080.png" width="308" height="80"></a></p>
<p align="center">&nbsp;</p>
<table border="0" width="100%">
<tr><td width="100%" style="border-style: solid; border-color: #FF9900; border-width: 1px; padding-left: 4px; padding-right: 4px; padding-top: 10px; padding-bottom: 10px; font-family: Courier New; font-size: 12">
<p align="center">Invalid URI...</p>
<p align="center">(Lightstreamer Server is up and running)</td></tr>
</table>

</body>

</html> on "Lightstreamer HTTP Server" from 127.0.0.1:7159
19-Feb-13 14:09:44,201|INFO |LightstreamerLogger.connections |SERVER POOLED THREAD 7 |Closed HTTP connection on "Lightstreamer HTTP Server" from 127.0.0.1:7159
19-Feb-13 14:09:44,496|INFO |LightstreamerMonitorText |Timer-0 |Total threads = 125, Total heap = 385875968 (free = 307237816), Sessions = 0 (max = 0), New sessions = [+0, -0], Connections = 0 (max = 1), New connections = [+24, -24], In-pool threads = 42, Active threads = 0, Available threads = 42, Queued tasks = 0, Pool queue wait = 0, NIO write queue = 0, NIO write queue wait = 0, NIO write selectors = 6, NIO total selectors = 48, Subscribed items = 0, Inbound throughput = 0 updates/s (pre-filtered = 0), Outbound throughput = 0 updates/s (0 kbit/s, max = 0), Lost updates = 0 (total = 0), Total bytes sent = 0, Client messages throughput = 0 msgs/s (0 kbit/s, max = 0), Total messages handled = 0, Extra sleep = 0, Notify delay = 0


I hided the LS_user and LS_adapter parameters.

by reading documentations, it looks like the lightstreamer server configuration does not support the Text mode protocol. if this is the case, how do I configure it to support Text mode? if not, what is the problem here?