I've got the same problem...
AttributeError: 'NoneType' object has no attribute 'lower'
Traceback (most recent call last):
File "C:/Users/XXXX/.qgis2/python/plugins\rivergis\rivergis.py", line 84, in
self.ui.actionRASXSAll.triggered.connect(lambda: r1d.ras1dXSAll(self))
File "C:/Users/XXXX/.qgis2/python/plugins\rivergis\ras1dFunctions.py", line 155, in ras1dXSAll
ras1dXSDownstreamLengths(rgis)
File "C:/Users/XXXX/.qgis2/python/plugins\rivergis\ras1dFunctions.py", line 101, in ras1dXSDownstreamLengths
if row[0].lower() not in ['channel', 'right', 'left', 'c', 'l', 'r']:
AttributeError: 'NoneType' object has no attribute 'lower'