Unable to use custom_regex validation on form fields

[erosiec]

'FormField' currently accepts a maximum of 10 arguments, resulting in an inability to pass in the 'validation_custom_regex' parameter for requests with 'custom_regex' set as the validation type.

Attempting to pass in 'validation_custom_regex' as an additional parameter through 'client.AdditionalParameters.Add()' throws an invalid parameter exception.

This blocks the ability to use 'custom_regex' validation type for form fields, since 'validation_custom_regex' is required to specify the regular expression.