This might be useful to others.
I recently produced 15 GPX files using rtkpost version 220.127.116.11 to geocode images using exiftool. Exiftool had success geocoding the images associated with 14 GPX files, but 1 GPX file caused a problem: exiftool gave error message “Warning: Second ‘60’ out of range 0…59 in File:Geotag (ValueConvInv)” and encoded none of the 200 targeted images.
The source of the error:
for one of the ‘times’, rtkpost wrote this in the GPX file it produced:
The times before and after were written correctly, one second before and one second after (23:29:59.00Z and 23:30:01.00Z).
The same ‘time’ (with the same error) was encoded twice in the GPX file, inside the ‘wpt’ and ‘trkpt’ tags.
Workaround: manually correcting the time where the error appeared in the GPX file allowed exiftool to encode the targeted images.
Not certain where in the PPK chain the bug comes from.