Symptoms

We have a simple page on our SharePoint 2013 Intranet that contains a K2 Worklist web part. Every so often, the web part is loses its connection with K2 (?) and displays the generic "The webpage cannot be found" error. There appears to be no consistency or series of events that precede this error, however, it usually happens when new versions of existing K2 Workflows are deployed.
 

Diagnoses

A number of errors being reported in the logs on our SharePoint site - mainly to do with synchronization issues with AD.

 

Resolution

It was determined that these issues are on the SharePoint side and K2 is the symptom, not the cause.

An external SharePoint consultant was able to clear the issues and the K2 app is now functioning as required.