AD-OD Sandbox error

I'm working on the AD-OD sandbox project, and I'm trying to add a Macbook to the AD, but when I try, I get the error "Unexpected error of the type- 14910 (eServerError) occured." It won't let me join. Everything that I've been finding on this error says "contact your AD admin...well, that's me and I have no idea what to do. What is that error and how can I fix it? I'm doing this on Windows Server 2003 R2 with SP2.