Symptoms

In K2 for SharePoint 2013, when K2 forms are used for New/Edit/Display items, and a list has a people column, a picker is then created on the forms when they are first generated using the K2 for SharePoint App. Upon hitting the "New Item" form on the list and entering in a value for the user, the picker resolves the user without a problem. However, upon hitting submit, an error message is displayed regarding the user defined in the picker:

"The user or group K2:ÂDOMAINUser] could not be found"

This may only happen for some users and not others.
 

Diagnoses

This was identified to be a problem with the groups the specific user defined in that picker is a member of. If one of the groups contains a special character, K2 stops resolving the user and throws the above error, but only after submit is selected. This then calls the smartobject method to "Create List Item" on the list, which is the actual method behind the scenes that fails with the above error.
 

Resolution

This has been identified as a bug and a fix can be provided (BUG 582467/645897) which seems to resolve the issue. Please contact K2 Technical Support regarding this fix on 4.6.11.