Error with a fresh install

I managed to get around a set of circular conflicts that accompanied a required downgrade of Django and appear to have cuDNN installed without issues, but now I have this error when I try to run any model in the Perceptilabs interface

Internal error in Error in create_response (action=‘getNetworkData’)
Traceback (most recent call last):
File “perceptilabs\”, line 264, in perceptilabs.mainInterface.Interface.create_response
File “perceptilabs\”, line 361, in perceptilabs.mainInterface.Interface._create_response
File “perceptilabs\”, line 556, in perceptilabs.mainInterface.Interface._get_network_data
File “perceptilabs\”, line 251, in
File “perceptilabs\”, line 338, in perceptilabs.createDataObject.subsample_data
File “perceptilabs\”, line 279, in perceptilabs.createDataObject.createDataObject
ValueError: max() arg is an empty sequence

Does anyone have any pointers about how I may address this?

many thanks - Mathew