Unfortunately it is not easy to explain in a completely 'untech language', because what you are trying to do is quite technical, but I will do my best.
The
GEDCOM (.ged) format allows customisations that different products such as
Family Historian and
Legacy use in different ways.
These customisations are identified by
non-standard tags with a leading underscore such as
_AREA,
_FILE,
_KEYS,
_NOTE, etc.
Only
standard GEDCOM tags are reliably transferred between products.
The problem tags you mention only relate to
Multimedia Record fields as follows, but you may come across others:
_AREA defines the
Link to Face/Detail frame.
_FILE defines the external media image
Linked File path.
_KEYS defines the
Keywords associated with the media.
_NOTE defines the
Note field.
Some of these can be easily resolved, but others may be more difficult to fix.
_AREA
The
Link to Face/Detail frame feature is unique to FH and does not export easily.
There is a V5 Plugin
Convert File Links you can install that converts each such frame to a separate image file.
You MUST use
File > Import/Export > Export > GEDCOM File and
Add All but
Exclude nothing, and select
Use Full File Paths for External File Links.
Then run the Plugin on this exported GEDCOM file.
_FILE
Strangely, the GEDCOM standard does not allow
Multimedia Records to link to external image files, but FH does by using
_FILE tags.
These can be eliminated by embedding the images within the GEDCOM file, and will resolve the problem assuming
Legacy supports this mode.
On the converted GEDCOM file from above use
File > Import/Export > Export > GEDCOM File and
Add All but
Exclude nothing, and select
Embed Multimedia in Export File.
[EDIT 18/07/2014]
Alternatively, select
Destination as
Family Tree Maker which replaces
_FILE with
FILE as detailed in how_to:exporting_gedcom_with_multimedia|> Exporting GEDCOM with Multimedia.
_KEYS
If you have not customised the media
Keywords then these can be ignored.
_NOTE
If there are not too many of these, then copy them afterwards by hand.
Alternatively, the GEDCOM (.ged) file could be text edited, or a small Plugin written to convert the Notes.