I have the free v.12 on my Windows laptop.  My computer at the school where I teach is an iMac with the licensed v.12 (not customised, as far as I know).  I've always been able to connect to that machine remotely, but as of a few days ago I 'm unable to make the connection.  This occurs if I begin in the usual way, OR if I log into the TV website and try from there.  In either case I press "Connect to partner", and the window for entering the password never comes up.  NOTE: A few days ago at school I let TV install a "helper tool" on the iMac.  I've no idea what it's for, and now I'm wondering if I should have done it.