why using RTCWCL cannot update for custom attribute ?
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Accepted answer
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If you create a custom attribute, it is not automatically added to existing work items. There is a special UI action that you need to perform for this this is called synchronize attributes. WCL does not automatically add the attribute, if it does not exist at the work item hence it says
Comments
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Thank you very much for your suggestions.
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When you open the EWM documentation (Library>Engineering.....) select EWM and your version, type "Synchronize Attributes" in the search field and then search you get this: https://www.ibm.com/docs/en/SSUC3U_7.0.3/ewm/com.ibm.team.workitem.doc/topics/t_updating_custom_attributes.html .
When you add custom attributes in the web UI, the editor provides you with a button to check usage of the attribute and also allows you to select to add it to all work items that do not have it.