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SMS Server and social conversations


Applies to Sinch Contact Pro from version FP18 onwards



There is an issue with Sinch Contact Pro and Conversation API or Sinch SMS integration, such as:  

  • Mobile originated (MO, from mobile to Sinch Contact Pro) messages are not received.  

  • Mobile terminated (MT, from Sinch Contact Pro to mobile) messages are not send.  

  • Attachments are not delivered. 

  • The SMS Server log has errors described in the Log errors table below. To read the SMS Server log,  follow the instructions below: 

    Log reading with blv.exe 

    1. Change the log level of SMS Server to trace. 
      You can also use debug for a short time, but we don't recommend using it in a production environment. No sensitive information is printed in the SMS Server log file while trace or debug levels are set.
    2. Go to Tools and Utilities folder of the installation media and run blv.exe. 
    3. To get started with the troubleshooting, you can use the following keywords: 
      • ERR|WRN|EXC
        This will highlight all errors, warnings and exceptions.
      • http 
        Integration is http based and with this filter you can catch all incoming and outgoing http actions. For example, http post for sending messages and http put for receiving message from Conversation API.
      • SMS or Facebook or WhatsApp 
        If you have several channels integrated, then you might want to use keyword to highlight log lines per channel.
      • UseSecureLogging
        By default this is not enabled. This enables message content to be displayed in the log for troubleshooting purposes. You should use this only for a short period of time.


Log errors:

Error Solution
 HTTP Timeout
  1. Check that the SMS Server has internet connection: 
    1. Log in to the server. 
    2. Open the SMS Server log (trace level) with BLV log viewer and activate Live mode.
    3. Open a browser and call the URL: 

      The SMS Server log should print: 

      HttpSmsServer::OnRequest /sms/sinchconversation/all  

      HttpSmsServer::OnRequest, Message is empty simply discarding it 

      If there's no print in the log when you try to open the SMS Server URL in the browser, check that the SMS Server mode is HTTP in System Configurator > System Management > Modules > SMS Server > SMS Interface > Session Object: HTTP  

      If you change SMS Server settings in System Configurator, restart the SMS Server. 

  2. Check that server has required certificates.
  3.  Use Wireshark to see what is causing the timeout.  
    If HTTP timeout happens for an outbound message (from Sinch Contact Pro to the client), you could also check proxy configuration and routing rule. 
HTTP 401 forbidden when sending message in the SMS Server log   This is most likely a configuration mistake in System Configurator > System Management > Messaging Services so check the procedure and re-create the configuration.  
HMAC256, CryptImportKey failed. Error: 0x3C24A58 Could not validate x-sinch-webhook-signature This log entry indicates that validation of connection has failed. Delete the connection and create it again in System Configurator > System Management > Messaging Services. You can also try to shorten webhook and access key password provided in Sinch Customer Dashboard.  
ERR> SMSApp: Unable to initialize session object! Check parameters from datasource  

The most likely reason is that the SMS Server mode isn’t HTTP in System Configuator > System Management > Modules > SMS Server > SMS Interface > Session Object 

Change the setting to HTTP, restart the SMS Server, and try again. 

Received HTTP status code 400 when sending rich content to customer.  

Messaging protocol in Conversation API for sending rich content has changed. If you have either FP17 or FP18 version, to fix the issue, install the hotfix: 

  • for FP17 
  • for FP18 

Remote service of type […] not found


In addition to this, Communication Panel shows Configuration missing.

This is a configuration error. Authentication ID and queue address (the part before @) are not matching. They should be the same. For example in case of direct Facebook integration:

  • authentication ID: 1234567890123
  • queue address:
    where 1234567890123 is the page ID of Facebook

CHttpSmsC: Could not create session handle ERROR_INVALID_PARAMETER

This error message may refer to an invalid proxy configuration. Check your proxy configuration in Infrastructure Administrator > SMS Server.


Other issues:

Error Solution
Attachments are missing 
  1. Check that System Configurator > System Services > Chat Settings > File Location Settings are defined according to the documentation. If you change settings, restart the Agent Server and SMS Server. 
  2. In case of the WhatsApp channel, check that you have GoDaddy certificate installed on your application server. 
  3. Check that public URL for attachments is available on internet and especially for WhatsApp servers. In practice WhatsApp loads content from the public URL and if WhatsApp is not able to access the share, the content is not loaded and visible for the user. To try out that the public URL is reachable, copy the URL from the SMS Server log and paste it to the browser.  
Rich content files are not received by the WhatsApp client from the outgoing WhatsApp message. Check that you have GoDaddy root certificate installed on the application server running the SMS Server component. To try out that the public URL is reachable, copy the URL from the SMS Server log and paste it to the browser.
Conversation Attached Data (CAD) is not visible in Communication Panel. 

Check from the visitor facing ECF Web Server logs that CAD WhatsApp is added to a chat  


  1. Check the *ECF_Visitor\EcfFrontEndServer-Java<-id>ECF_Visitor<date>.log file 
  2. Ensure the log level is at least TRC.  
  3. Filter log with "attached_data":{ and you'll find chats that have some CAD.  


If the chat arrived with CAD and is provided with CAD keys, the issue is in Sinch Contact Pro. Check the Chat Server logs.  

Related information:



Error in SMS Server log, problem started after 15/06/2023: ERROR_WINHTTP_CANNOT_CONNECT

Reason: there was an update made to Conversation API that changed the allowed ciphers. Please find a list of supported ciphers below:

Preferred TLSv1.3 128 bits TLS_AES_128_GCM_SHA256 Curve 25519 DHE 253
Accepted TLSv1.3 256 bits TLS_AES_256_GCM_SHA384 Curve 25519 DHE 253
Accepted TLSv1.3 256 bits TLS_CHACHA20_POLY1305_SHA256 Curve 25519 DHE 253
Preferred TLSv1.2 256 bits ECDHE-RSA-CHACHA20-POLY1305 Curve 25519 DHE 253
Accepted TLSv1.2 128 bits ECDHE-RSA-AES128-GCM-SHA256 Curve 25519 DHE 253
Accepted TLSv1.2 256 bits ECDHE-RSA-AES256-GCM-SHA384 Curve 25519 DHE 253


Jukka Suhonen, Contact Pro Senior Product Engineer