Problem Description:
I am training a deep learning model in ArcGIS Pro.
The input training folder (from Export Training Data For Deep Learning) works fine and is recognized by the tool.
The issue is with the output folder parameter:
The tool requires the output folder to be empty.
I create a new empty folder (verified there are no files inside).
When I run the tool and set that folder as output, I still get an error saying the parameter is not valid.