Could you copy the error log as text (not as image) so that we can see it completely?
raise ValueError("lengths array has to be sorted in decreasing order")
ValueError: lengths array has to be sorted in decreasing order
I guess it is because of valid_iter. There is a bug there. I mentioned it here. It seems not fixed.
use pytorch text v0.1.1 instead of pytorch text v0.2
source code: https://github.com/pytorch/text/archive/v0.1.1.tar.gz
it works for me.