Your question belongs on the TMG Maillist but here goes:
First - - if you still have the attempted GEDCOM in TMG on your computer get rid of it this way.
Know the file name used to save that GEDCOM. Open TMG.
If the 'sample' dataset is on screen great. Begin with step 2 below.
1. You cannot delete a TMG dataset that is open.If the GEDCOM dataset is on screen, click File, Sample (down at the bottom of the window. This will close the GEDCOM dataset and open the sample dataset..
2. Read the bottom part of the TMG big manual, page 128, about 'Delete a Data Set'. 3. Do what the TMG manual says.
Don't worry about messing up Roots III. You are now in TMG and are deleting the COPY of the former Roots III .edb. Your Roots III program and .edb (et al) are as they were before.
Now that you don't have the Roots III stuff in TMG. . .
4. Read your big TMG manual pages 195 and 213-215.
5. Do it.
6. After you have GenBridged the Roots III project into TMG, DO NOT begin changing or adding stuff to this TMG dataset. Explore what happened with the choices you made during the import.
IF you find you don't like some of the choices you made, DELETE the new (formerly Roots III) dataset in the same way you did above.
Reimport the Roots III stuff making other choices for what you didn't like. Explore those choices. Delete and reimpot as needed until you get what you want.
Do not be surprised if you find things are missing. They are probably not entered in Roots III. Can't import what is not there. If you don't believe that, open Roots III (after closing TMG), and see if you really entered what you thought you did.
If the above doesn't work for you, I suggest you post at http://genforum.genealogy.com/tmg/all.htmlhttp://genforum.genealogy.com/tmg/all.html or, better yet, subscribe, via email, to TMG-Dfirstname.lastname@example.org. Send a message containing only the word "subscribe" (without quotes) to that address.