If "Validate Certificates" is enabled, the Trusted Authority certificates represent the entities that are to be trusted.

Supported Certificate Types to load Trusted Authority Certificates are PEM, PKCS7 and PKCS12.

Authority Certificate Type field will be automatically updated depending upon extension of the certificate entered. If the field is NONE i.e., certificate is not supported then it will not load. If the field is PKCS12, In the Password: field corresponding PKCS12 password should be entered.