Symptoms
Task is not available for one of the users to which it has been assigned. There is a task with two participants. One of the assigned users cannot open this task and cannot see it in worklist web part. But the notification of the task assignment has been received by this user.
Administrator can see this user as a participant in ViewFlow in Activity Summary on Participants tab and in K2 workspace management (Workflow Server > Worklists). Moreover, if administrator redirects task to himself and then back to this affected user, user is able to see this task.
Diagnoses
As when an administrator redirects task to himself and then back to this affected user, user is able to see this task we can be sure that this is not a user’s filters configuration problem or problem with identity cache.
It is possible to see in K2 host server logs that at the time of task assignment no errors being logged and task is being assigned to two users:
"Debug","General","28059","DestinationActivity","ProcessInstance.CreateDestinations","28059 Tenders department.Destination: K2: DOMAINNORMAL_USER ","anonymous","0.0.0.0","K2SERVER:C:Program Files (x86)K2 blackpearlHost ServerBin","2328723455","4663569483b3417bace4c840fbb86fc4","""Debug","General","28059","DestinationActivity","ProcessInstance.CreateDestinations","28059 Tenders Department.Destination: K2: DOMAINAFFECTED_USER ","anonymous","0.0.0.0","K2SERVER:C:Program Files (x86)K2 blackpearlHost ServerBin","2328723456","c43598d80c254d12a62cd911ddedfd11",""
As aforementioned things are in order, we checked Server.Actioner table for any leading/lagging whitespace characters in the username of affected user.
Resolution
“Duplicate” entry containing space for affected user in Server.Actioner table can cause such issues. Removal of it should resolve this issue. For example such incorrect entry may come from source table for SmartObject which is used by process.
Usually wrong entries in Server.Actioner table caused by a Destination Rule configured to accept User Input through a DataField, i.e when user types in the next Destination User by filling out a form. Wherever that user input is being done, e.g. on some frontend, this interface should be responsible for trimming the value, because K2 unable to define whether the whitespace is intentional or not.
