Error Message: "Improper table entry name TRIMBLE GPS PATHFINDER (or PORKY'S) on line XXXX. Invalid or incomplete DXF input -- drawing discarded."

Problem/Symptom:
Getting an error while trying to open a DXF in AutoCad.

"Improper table entry name TRIMBLE GPS PATHFINDER (or PORKY'S) on line XXXX. Invalid or incomplete DXF input -- drawing discarded."

The DXF will not open in AutoCad.

Environment:
This resolution applies all version of Geosoft and AutoCad. Trying to open Geosoft DXF files in AutoCad.

Resolution:

Option #1)
1. Open the DXF in NotePad.
2. Find and replace TRIMBLE GPS PATHFINDER with YEMENSTR
3. Repeat the process and find and replace TRIMBLE GPS PATHFINDER.TTF with YEMENSTR.TTF
4. Save the file as a DXF - be sure to Save directly (don't use the Save As function)

Option #2)
Look in the fonts directory (C:\WINDOWS\Fonts) and in C:\Program Files\Geosoft\Oasis montaj\fonts and look for a font called TRIMBLE GPS PATHFINDER or PORKY'S.

If they exist there, it is suggested that you temporarily move this font out of these two directories and try the DXF export again. You may however see this error message with any number of fonts that AutoCAD doesn't like, so you will need to continue doing this until all unusual fonts (i.e. those that AutoCAD doesn't understand and those that appear in that error message you received) are gone in order for the export to be successful.

If this is too much, it is suggested that you remove all of the fonts from the C:\WINDOWS\Fonts and C:\Program Files\Geosoft\Oasis montaj\fonts directories and leave behind only a few standards like Arial, Times New Roman etc., instead of removing all the unusual fonts one at a time. Or, you could contact AutoCAD support and see if they have ideas. Perhaps AutoCAD has a function to add the recognition of new fonts.

Also delete or move any other fonts that may have spaces, or errors or full path names. If this doesn't help, you can try checking under Edit > Settings > Advanced (in Oasis), expand the APPSettings and look for the Font Settings. Expand this one and you should see the AutoCAD Font settings; check here to see if any of these fonts are problematic.
Users in the past have moved (or deleted) the problematic fonts from those directories and re-exported the DXF and had no problems on importing in AutoCAD

Root Cause:
The problem has to do with a font file ("TRIMBLE GPS PATHFINDER" or "PORKY'S") that AutoCAD doesn't like. AutoCAD does not like spaces and full paths in font names, and may not like the spaces in the TRIMBLE GPS PATHFINDER or the ' in PORKY'S.