Hi @user48945, part of the issue is that you are using the labelmap from CVAT, and not a labels.txt you created like this:
dog leash
Your labels.txt should have one class name per line.
The way to debug this is to run train_ssd.py with --debug-steps=1 --batch-size=1 --workers=0
and uncomment this line of code:
It will then print out the image ID of each image as it’s loaded. The one right before the exception occurs is the one that causes the error. You can then inspect this image’s XML, and either fix it’s annotations or remove it from the ImageSets.