I know this is an old thread, but I’m just starting with Encore (and the whole suite) and this just came up for me. I don’t see anyone really answering the question, so I’ll just jump in.
On the left of your screen, go to the project tab. On the right, go to the properties tab. Where it says “Title remote not set”, grab the pickwhip and drag it all the way across your screen to the title page you’ve indicated in your project tab, and let go. Done.