Yes, everybody has this issue now with Radeon Render at least on Mac. Go back to the beta version released on May 15th and you will be ok for now.
While this version of RPR and Blender do not like each other, there is a new version coming very soon that will fix this issue. The issue is that the Blender Plug-in API received some massive changes and as a result most plugins are currently broken. Feature freeze has happened for 2.8 though so the fix is almost here.