Wim would be better placed to comment, but having looked at the code, I would guess that the best edit to work around this would be in the method createSingleResonanceMeasurement() in /usr/local/ccpnmr/ccpnmr2.4/python/ccpnmr/format/converters/DataFormat.py.  So the first thing it could do could be:

  if rawMeasurement.value is None:

    return

(I think the value must be None, given what the error message says.)

Well, I would normally say “return None” but there is just a plain “return” in the code below so the above is compatible with that.  (They are the same thing in Python but the plain old “return” always worries me because it implies, to me at least, that the return value is unimportant, whereas here is it important.)

Wayne