Can't unschedule---HELP!

Hello, We're trying to unschedule an email and the dashboard won't allow us to. We get a red bar that says we can't. Might this have anything to do with the machine we're using or being inside the twelve hour window of publishing? Meaning, it's 9:12p on 10/23 and the email is scheduled for 7a on 10/24. Seems like that shouldn't matter but it's the only guess we have at the moment.