Symptoms

Tasks have been assigned to users (confirmed from K2 Workspace Worklists) but not visible when calling worklist item from K2 Designer View.

 

Diagnoses

Could not open viewflow, or access the K2 worklist control. (returned no results)
Ensure that the HTTPS (SSL) Setup is complete.
Ensure that the viewflow config is setup correctly (Environment library)
 

Resolution

After changing the environment fields to HTTPS and running SQL scripts to sort out the web service url values. (as well as changing the default environment)

Then editing the C:WindowsSystem32inetsrvconfigApplicationHost.config under the "site name" section, changing the binding here and adding the HTTPS binding. This resolved the worklist control issue.