problem about training

[atomishcv]

when i train the code ，the program feedback such information：
0%| | 0/1250 [00:05<?, ?it/s]
Traceback (most recent call last):
File "C:\Users\aust\Desktop\Coarse_LoFTR_TRT-main\train\trainer.py", line 154, in train_loop
self.scaler.scale(loss).backward()
File "C:\Users\aust\anaconda3\lib\site-packages\torch_tensor.py", line 255, in backward
torch.autograd.backward(self, gradient, retain_graph, create_graph, inputs=inputs)
File "C:\Users\aust\anaconda3\lib\site-packages\torch\autograd_init_.py", line 147, in backward
Variable._execution_engine.run_backward(
RuntimeError: Function 'KlDivBackward' returned nan values in its 0th output.
python-BaseException

it looks like the loss function has problem?