When using SharePoint Integration in a K2 process it might be possible that you see this, instead of the task view for the user:

In this case, in my environment, running the K2 for SharePoint Configuration Wizard (click “Next” until the end) and at the end running “Navigate to ‘Activate All K2 Features and K2 Configuration Settings’ page in order to activate the K2 features to the first site collection” and do this activation in the site collection, this message appears, fixes this issue.

Don’t know what the reason for this message is. Even restarting the SharePoint Timer service on all SharePoint machine didn’t fix this issue.