I copied a workflow from a list to the same list (while renaming it). The copy of the WF works fine however it left the old workflow so that SPD will not bring it up into edit regardless of the technique I try. The old one continues to be triggered properly but I can stop it using the workflow status screen. The workflow in question is very long but not near SP limits. This is a 2010 workflow on 2013 server. This behavior did not happen on a separate test list (both workflows on the test list are editable and execute properly) .