Symptoms

in the k2 designer there are several SharePoint activities. The first field in any of these activity wizards asks for the SharePoint site url. I enter the url and the designer gets a response:

The request failed with HTTP status 404: Not Found.

This indicates it is not a security problem since it’s a 404 error. I tried accessing the site from the K2 server in a browser and it is able to see it just fine. Why can't the designer activity wizard see the SharePoint url?
 

Diagnoses

The error was caused by K2 app pool account is trying to access K2SPDesigner.asmx web service in C:Program FilesCommon FilesMicrosoft SharedWeb Server Extensions14isapi. Since the customer did not install K2 for SharePoint on the SharePoint server causing the web service not to be there.
 

Resolution

Customer will need to install K2 for SharePoint on the SharePoint server in order to use the integration for SharePoint 2010 or upgrade to SharePoint 2013. With SharePoint 2013, customer will not need to install K2 bits on the SharePoint server.