@ptrblck @albanD apologies for the direct ping. Unsure who to ping.
I am facing this issue too but I know this should not be happening. All weights should be being used.
Is it possible to improve the error message and display the name of the weights causing this issue? It would help me to even start where to debug this.
My model is a simple 5CNN and it passes mini-imagenet data. There shouldn’t be this issue – but would love to get better messages 
RuntimeError: One of the differentiated Tensors appears to not have been used in the graph. Set allow_unused=True if this is the desired behavior.
related: Error from maml, gradients var not found -- why? · Issue #314 · learnables/learn2learn · GitHub