Errors When Train Custom Dataset with c2/SLOWFAST_8x8_R101_101_101

I'm now trying to train SLOWFAST_8x8_R101_101_101 with my dataset and meetting error:

`RuntimeError: DataLoader worker (pid(s) 2133, 2135, 2138, 2139) exited unexpectedly`

But, I can train with C2D_8x8_R50.

And the second question, you can tell me the directory output model when training with google colab? When I continue to train it can load from the last checkpoint but I can find this file with the search tool, and "checkpoints" folder is empty.
I have used google colab, run this command to fix errors have space in [My Drive]

`!ln -s "/content/drive/My Drive/action_recognition/slowfast/" "/content/"`

and run your code

```
!python "/content/drive/My Drive/action_recognition/slowfast/tools/run_net.py" \
--cfg "/content/drive/My Drive/action_recognition/slowfast/configs/Kinetics/c2/SLOWFAST_16x8_R101_50_50.yaml" \
DATA.PATH_TO_DATA_DIR "/content/drive/My Drive/action_recognition/slowfast/dataset" \
NUM_GPUS 1 \
TRAIN.BATCH_SIZE 16 \
```
Can you help me with these issues?
Thank you!