When trying to Inactivate Item via the Item Connector file (column NOTACTIVE), you could receive a message saying that Inactive revisions are not supported.
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When using Connector to Inactivate Items, the Item details that are on the connector file should not have any updates. Just the NOTACTIVE column that should be set as Y (yes).
The common issue is with the Revision Date/Time. The revision date and time should be same as set on the Item's Record database (Generally this is UTC potentially unlike your item report whicih may convert the revision to the admin's timezone), otherwise it will not allow the connector to inactivate the Item and it will give this exception.
sap sf lms Using Connector to Inactivate Items, Inactive revisions are not supported, Item revision date / time, Connector failed exception 1321 , KBA , LOD-SF-LMS-CON , Connectors , Problem