Before starting to mask a database, the masker will do a validation step to ensure that masking is likely to succeed. It will check the contents of the masking. configuration JSON file make sense, and will compare its contents to the schema of the database being masked. If it finds any errors, masking will not start and the masker will exit with one or more validation errors.

Validation errors fall into two categories:

• File errors - there is an error in the masking file
• Schema errors - there is an incompatibility between the masking file and the database schema

Each validation error will have a help link associated with it. Following this link will explain more about the error, and show how to address it.