Remember that, if necessary, you can repeat the import as many times as you need, until you get it right. Don’t be afraid to experiment.
Check that your TMG project appears to load OK in TMG. Consider running “Validate File Integrity” within TMG (to access this click ‘Maintenance’ on the ‘File’ menu). If after the import you find something that looks wrong in Family Historian, your first response should always be to go back to the original and see how it looks there. Family Historian cannot correct errors in the original.
Tag types in TMG can optionally be associated with a GEDCOM tag. For example, the GEDCOM tag for Birth is ‘BIRT’ and the GEDCOM tag for Death is ‘DEAT’. It is important that the GEDCOM tags are correctly set. In particular, it is important that the main Birth tag type in TMG should have the ‘BIRT’ GEDCOM tag, and the main Death tag type should have the ‘DEAT’ GEDCOM tag. Family Historian will match TMG tag types to its own fact types, and it uses standard GEDCOM fact tags to do it. Try to ensure that no two tag types share the same GEDCOM tag, unless you wish to take the import option to merge tag types on import. In that case, Family Historian will assume that the tag type definitions to be merged, are very similar to one another, or identical. To learn more, see “Enable Fact Definition Merging” in the Help for the TMG Import Options.