I had a somewhat similar experience also. When I installed the new version of DAZ Studio (1.7), I received the same message as you got when trying to open Bryce 6 (not 6.1). I contacted DAZ tech support, who informed me that this would not be fixed & that I would need to upgrade to Bryce 6.1. I chose not to & instead uninstalled DAZ Studio 1.7 & reinstalled the previous version (1.3). That fixed my problem. So I think you can fix your problem by either upgrading to Bryce 6.1 or installing DAZ Studio 1.3.

As a matter of principle, I understand that DAZ is trying to integrate BRYCE & DAZ Studio to improve usability, but I think it's a terrible design flaw when a product I paid for stops working when I install an upgrade to a separate, free product. I haven't had any significant problems with Bryce 6, have no need for the improvements in Bryce 6.1, & don't like being forced to upgrade before I'm ready. At the least, they should have tested DAZ Studio 1.7 with Bryce 6 & warned users ahead of time that they were incompatible...  

"Every child is an artist. The problem is how to remain an artist once we grow up." - Picasso