Symptoms

After deploying a package with the K2 for SharePoint app, an exception gets thrown on attempt to redeploy the workflow, complaining of a missing reference in the title.
 

Diagnoses

A guidance was specified on the exception, advising on checking the 'Title' field in Workflow settings. Remapping that field (screenshots attached) solves the issue and it is the workaround of the problem.
 

Resolution

A tfs item was logged against this issue and the problem is slated for the Appit 1.3 release. When this happens, there is also going to be a fix provided for the issue in K2 for SharePoint.