Data masking is a complex operation and can run into issues because of a variety of reasons- Data, Metadata, and Salesforce Platform limitations. DataMasker has a way to capture exceptions in a custom object. This functionality only needs to be enabled, if Cloud Compliance support requests so.

Here are the steps:

Step 1: Search Custom Metadata Type

In your Salesforce Org, search for “Custom Metadata Types”

Step 2: Update Metadata Value

Click on ‘Manage Records’ for ‘DM App Config’

Click on the ‘Edit’ link

 
Update the value to “True”

The value of ‘Label Capture_Exceptions’ is now successfully set to “True”. This means DataMasker will now capture metadata exceptions.