When I open MacJournal, I get the error: "This document may be opened by another user." What do I do?
This is a mechanism for making sure that you don't open the document in more than one place at a time. However, it can get tripped up if MacJournal did not exit cleanly or if you copy the data file while MacJournal is running. Go to the data file in the Finder, control-click to show the package contents, and delete the Document.lock file. You should not see the message again. In the future the app will do this for you when you opt to "Open Anyway".