1985098 - Activity activation is failing due to 404 Not Found error

The activity activation is failing with the following error:
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An incompleted Integration has been detected: BS:<*> SC:<*> is locked out by request <*> for Integration! Initialization request <*> has been created

Communication error when performing integrations. Unexpected response status [404 Not Found]. Request FAILED.
[EXCEPTION]


The following problem(s) occured  during request processing

at com.sap.tc.cbs.server.proc.impl.ActivationPostProcessor.finalizePostprocessing(ActivationPostProcessor.java:79)
at com.sap.tc.cbs.server.proc.impl.PostProcessor.applyChanges(PostProcessor.java:91)
at com.sap.tc.cbs.server.proc.impl.BuildPostProcessor._process(BuildPostProcessor.java:190)
at com.sap.tc.cbs.server.proc.impl.Processor.process(Processor.java:140)
at com.sap.tc.cbs.server.proc.RequestHandler.doProcessing(RequestHandler.java:699)
at com.sap.tc.cbs.server.proc.RequestHandler.doPostProcess(RequestHandler.java:250)
at com.sap.tc.cbs.server.proc.RequestHandler.process(RequestHandler.java:149)
at com.sap.tc.cbs.server.proc.RequestHandler.run(RequestHandler.java:125)
at com.sap.tc.cbs.server.rt.threads.PerpetualRunnable.run(PerpetualRunnable.java:109)
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• SAP NetWeaver all releases
• SAP Composition Environment all releases

cbs, dtr, activity, activation, 404, checkin, incomplete integration, "Communication error when performing integrations", "Unexpected response status", ActivationPostProcessor, finalizePostprocessing , KBA , BC-CTS-CBS , Component Build Server & Component Infrastructure , Problem