SAP Message WZ344 - You cannot complete work item &1 for user &2

Diagnosis
You tried to complete work item <(>&<)>1 for user <(>&<)>2, but you donot have authorization for authorization object S_WF_WI (WI_TYPE = 'W',TASK_CLASS = <(><<)>task class of the task underlying the work item>,WFACTVT = '13').

System Response
The system prevents the completion.

Procedure
Please obtain the required authorization from your workflow systemadministrator.