Since you are using MacOS and not many users on this forum, I advise posting the same on https://discuss.pixls.us/ forum.
Whatever OS you use, Gimp has to "find" the RT installation so that the built-in RAW plugin opens the image in RT before sending it back to Gimp when RT closes. This is know not to work in the past. AFAIK one of the RT developers does post on pixls.us Give details of your DNG image version as well, that might be the issue.
Whatever OS you use, Gimp has to "find" the RT installation so that the built-in RAW plugin opens the image in RT before sending it back to Gimp when RT closes. This is know not to work in the past. AFAIK one of the RT developers does post on pixls.us Give details of your DNG image version as well, that might be the issue.