Hello, Irene:
Did you try simply logging off and back on, or restarting your Mac? This also kills the process, and is an easier resolution for those who are not comfortable with using the Activity Monitor to end processes. Once logged back on, you should no longer receive the -1712 error.
As this is a Mac OS 10.8.2 issue, and not an EndNote or Word issue, I’m afraid rolling back to X5 will not help resolve this. Please see the posts above from Mathilda for a link on how to contact Apple regarding this issue.