[mmdetection/ mmrotate] Loss Nan

https://github.com/open-mmlab/mmdetection/issues/2739#issuecomment-631196300

Loss becomes NAN after a few iterations · Issue #2739 · open-mmlab/mmdetection

TO DO LIST

1. check if the dataset annotations are correct
2. reduce the learning rate
3. extend the warmup iterations
4. add gradient clipping