Hi,
System:
Ubuntu 18.04 using the anaconda env, TF and DLC version provided here: https://github.com/AlexEMG/DeepLabCut/tree/master/conda-environments
GPU/drivers/CUDA version:

I am trying DLC using the GUI for the first time and so attempting to train a network using a small data set (20 labelled images). Everything seems to be working smoothly and I am also able to import tf and start a session so tf seems to be working okay:

However, when i click 'train network' I immediately see this error message:

It seems like I have forgotten to do something when setting up the dataset but I cannot work out what it is, please help! Thanks!
Fix coming up!
Most helpful comment
Fix coming up!