A delete-update conflict between peer %1!s! (incoming) and peer %2!s! (on disk) was detected and could not be resolved automatically. ...

A delete-update conflict between peer %1!s! (incoming) and peer %2!s! (on disk) was detected and could not be resolved automatically.  The incoming delete was skipped by peer %3!s!. The conflict has to be resolved manually to guarantee data convergence between the peers. For steps on how to resolve the conflict refer to BOL.