Symptoms
PDF Converter fails to load SmartForm View for conversion to PDF due to SSL certificate error
Diagnoses
When using the PDF converter action in a process to load and convert a view to a PDF, A SSL certificate error is seen when the converter tries to load the url of the view. The host service and smartforms are located on the same server. The view can be accessed normally via browser on the server as both an admin and as the service account and both do not display SSL errors.
Resolution
The Server will use the Settings configured via IE for that User . So any Proxy/Trusted Site configuration that needs to be done needs to be performed and set in IE logged on with the K2 Service account
see if this helps get more detail around the error
http://help.k2.com/kb001626.aspx