Symptoms

There are several roles setup and used as workflow destinations. All of the roles have at least one role item. No email notifications are being generated and no worklist items are appearing in the user's worklists. The HostServer log has multiple entries of the following error:

"UMEmptyQError","K2DestQueue.RunDestQueue","24148 The User Manager 127.0.0.1 returned an empty queue."...
 

Diagnoses

Usually this error occurs if a role does not have at least one role item. If the role items is a Smartobject call/group test if that Smartobject or group is returning results or not. To check the members of a group one can execute the out-of-the-box UMUsers Smartobject andgt Get Group Users method under the "All Smartobjects" Category in the Smartobject Service Tester Tool. Specifying the group name, usually "domaingroupname" and "K2" being the LabelName if it is an out-of-the-box active directory groups.
 

Resolution

Customer indicated that the error has been resolved after restarting the server: "The server and K2 services were restarted and this fixed the issue. Not sure why, but there were Windows updates applied prior to the issue and perhaps another clean boot of the server and K2 services resolved the issue." Perhaps the update caused a group/smartobject resolution issue.