AI Fabric Pipeline Error Currency Classification Model Training Failed

How to resolve the error " Classification Model Training Failed" observed in the AI-Fabric training pipeline?

Issue Description: " <Class name>Classification Model Training Failed" error observed in the AI-Fabric  training pipeline. Below is the exception obtained: 
Exception: currency Classification Model Training Failed

Resolution: This error occurs if there is classification field created, but is not labelled for any of the documents.
UiPath recommends labeling requirements as shown below:

Refer the link , for more details.

In case, data is exported from data manager without labeling the classification field and if it is really not required, then classification fields details needs to be removed from the schema.json file .