Symptoms

At some point, it may be necessary to add new WFE server into SharePoint 2010 farm that has K2 for SharePoint components installed and apart from general process of adding new server into SharePoint farm, it will be necessary to perform certain tasks from K2 side.
 

Diagnoses

When adding extra WFE server into SharePoint 2010 farm that has K2 for SharePoint components installed you need to install K2 for SharePoint components on this server.
 

Resolution

In case of K2 4.6.8 and SharePoint 2010, what is necessary from K2 side is to run the K2 blackpearl setup.exe on a newly added WFE server and it will automatically detect that this is SharePoint server and pre-select the K2 for SharePoint features.
After installation is complete, Central Administration server will have to propagate all the K2 features across to this WFE server through the SharePoint Timer Job. This process usually takes some time (normally, this should be completed during the day).

Please refer to the following section of K2 documentation for information on installation of K2 for SharePoint in distributed environment:
https://help.k2.com/onlinehelp/k2blackpearl/icg/4.6.8/webframe.html_install_k2forsharepoint.html
This article covers prerequisites, installation, additional SPN/Delegation configuration and what to check to validate your installation.
It may be also necessary to check K2 for SharePoint required permissions:
http://help.k2.com/onlinehelp/k2blackpearl/icg/4.6.8/webframe.html_k2_for_sharepoint_-_required_permissions-sp_core.html