Negative loss with UNet

Hi, when I run the UNet model implemented as listed in

with the default run command python

I see negative loss values and 0 Best validation mean DSC: 0.000000.

loss for step: 622 = [-0.9068316221237183]
loss for step: 623 = [-0.9329317808151245]
loss for step: 624 = [-0.9376015663146973]
Best validation mean DSC: 0.000000

This code is using Torch 1.10 on Nvidia GPU with CUDA 11.
Is there something that needs fixing in the code (dataloader etc.)?

Could you check which loss function you are using and what the expected inputs are?
I would guess that either the model outputs or targets do not contain the desired values.

The loss is DiceLoss.