Symptoms

We are getting the following error while trying to point my event to the SharePoint 2013 site I keep getting an error
"The Underlying Connection was closed: Could not Establish Trust Relationship for the TLS/SSL secure channel"
 

Diagnoses

We can successfully create SmartObjects and views from the library in SharePoint.
But the issue seems to presist

 

Resolution

• Do you have DNS and line-of-sight to the server?
• Are you using the correct name from the certificate?
• Is the certificate still valid?
• Is there a certificate trust chain issue? if you browse from the server to the soap service, can you get SSL? (see below)

Since you are trying to access the HTTPS web service we need to add the SSL to the SharePoint Trusted Root Authority.
http://help.k2.com/onlinehelp/k2forsharepoint/icg/current/default.htm_install_topics/before/before_you_begin.htm_tracksearch=ssl
http://help.k2.com/onlinehelp/k2blackpearl/icg/current/webframe.html_introduction_to_ssl.html_tracksearch=ssl
http://help.k2.com/onlinehelp/k2blackpearl/icg/current/webframe.html_ssl_certificates.html_tracksearch=ssl

This issue is can also be caused by the certificate chain becoming invalid when periodic checks are made to validate the SSL certificates. This is a known issue when using SSL in SharePoint. For more information and a workaround, see the Microsoft KB Site slowness due to SharePoint STS Certificate CRL checking (http://support.microsoft.com/kb/2625048).