Symptoms

When attempting to access K2 Appit for SharePoint from the K2 Application portion of the SharePoint ribbon from a list/ library, the button for this option does not appear.
 

Diagnoses

This issue was caused when the Oauth token for the environment expired. An email was sent to the global administrator for the site collection to refresh the OAuth tokens.
 

Resolution

Following the instructions given by the email, the link provided in the email to refresh the tokens was utilized. After this the K2 for SharePoint app was removed from the Site Contents, then reapplied which fixed the issue.