Error: "Invalid Sequence Flow: it connects a node located in main flow ...

Question

I have a error in BPM flow:
Invalid Sequence Flow: it connects a node located in main flow (#1) to a node located in a Boundary Event flow (#2)
The component is a "Manual Activity" (#1) connected a "Human Task" (#2)
A another error with the same message is a "Exclusive Gateway" (#1) connected a another "Exclusive Gateway" (#2)
Can help me?

Answer 1

Thank you Jasmin and Diego. Your replies made me look carefully at my code and I found that I was not updating the repository with Document without the Policy added. I was doing the following:
RMSecureDocumentResult protectDoc = documentManager.protectDocument(unproctDoc,                "yabby_traps_kill_platypus.pdf", policySet, lcPolicy.getName(), null, null, null);
r.getContent().setDataDocument(unproctDoc);
repositoryClient.updateResource(r.getPath(),r,false);
Instead I should have been doing the following:
RMSecureDocumentResult protectDoc = documentManager.protectDocument(unproctDoc,                "yabby_traps_kill_platypus.pdf", policySet, lcPolicy.getName(), null, null, null);
r.getContent().setDataDocument(protectDoc.getProtectedDoc());
repositoryClient.updateResource(r.getPath(),r,false);