Running into the same error with the ComfyUI console logs giving
"invalid prompt: {'type': 'missing_node_type', 'message': "Node 'Face Bounding Box' not found. The custom node may not be installed.", 'details': "Node ID '#2'", 'extra_info': {'node_id': '2', 'class_type': 'FaceBoundingBox', 'node_title': 'Face Bounding Box'}}".
Possible cause I found checking I noticed that my import of "ComfyUI_FaceAnalysis" through ComfyUI mentioned in the ReadMe failed. I'd assume it's due to it requiring DLib or InsightFace. Trying to install those and get it working with Comfy have been a pain I'm working through.
Not 100% if this would be the cause of the issue, just wanted to chime in with my own findings. Hope this helps!