And now the question: how to reproduce the issue...?
I logged in to your site, updated ReReplacer, and am going through different articles. Opening the Yootheme Builder gives me no errors anywhere...
I'd just like to add here that I had the exact same error being reported when I updated to 12.3.2. I do not use any yootheme products at all. I am using Gantry 5 and Manticore theme. When I disable rereplacer the error went away, regressing to 12.3.1 also made the error go. Now I just tried the 12.3.3.DEV build and that DOES fix the issue for me too.
So, not sure I quite understand it all but I thought it would be good to let you know.