Known issues

AttributeError: ‘MultiDataLoader’ object has no attribute ‘sampler’:

This bug has been fixed in pytorch-lightning only recently and appears only in the multi-gpu mode. Quickest fix (for now) is to use a single GPU or revert to version 0.7.5 with pip install pytorch-lightning==0.7.5.

TypeError: forward() takes 2 positional arguments but 3 were given

This error causes other errors to appear, displaying multiple stacktraces, so the last line you actually see is:

::
TypeError: ‘NoneType’ object is not iterable

The current fix is to revert pytorch-lightning to version 0.7.3.