This article was created in response to a support issue logged with K2. The content may include typographical errors and may be revised at any time without notice This article is not considered official documentation for K2 software and is provided “as is” with no warranties.
Regularly unhandled exceptions consistently reporting an HTTP Exception: "Cannot redirect after HTTP headers have been sent" warnings are being noted multiple times per day.
An error is seen regularly in the event viewer logs:
"Event code: 3005 Event message: An unhandled exception has occurred. Exception information: Exception type: HttpException Exception message: Cannot redirect after HTTP headers have been sent."
This issue is being investigated and reviewed for future release of the product: "K2Blackpearl Form WorklistControl - 'Cannot redirect after HTTP headers have been sent.'"
These warnings in Event Viewer is not something to be worried about - especially if K2 is functioning fine.
Referencing article: https://social.technet.microsoft.com/Forums/Azure/en-US/bd630981-49ff-4113-bb6a-173dcc6829e7/401-unauthorized-problem-fba?forum=sharepointadminlegacy