Symptoms

We have developed and tested a custom K2 based application on our local developer VM and later in DEV environment. However when site content and K2 packages are promoted to QA , we were not able to deploy workflows in one of the list and getting an error with message.

The "SourceCode.SharePoint15.DeploymentTask.Task" task failed unexpectedly.
System.Exception: Service: SharePointIntegration
Service Guid: 71810da1-81e2-4f22-8cf2-4011dacfdf42
Severity: Error
Error Message: Thread 1: Access denied. You do not have permission to perform this action or access this resource.
 

Diagnoses

The issue was related to missing permissions for the K2 Service account. It did not have permissions to create/delete Event Receivers and thus could not be deployed with Item Added/Updated etc.
 

Resolution

The issue was resolved by deleting the SharePoint Event Receivers and redeploying. K2 was then able to correctly add the Event Receivers. I think the K2 Service account has create rights, but not update rights and so this is why we are running into the issue.