CRED plugin allows you to build forms for front-end user registration and editing. These forms can include user fields and display them with your HTML styling. They also support input validation and automatic email notifications.
When you ask for help or report issues, make sure to tell us the structure and the settings of your form.
Solution:
No.
"cred_save_data" hook belongs to Toolset forms and it will only triggered when you submit the form that is created using Toolset.
If you are using another plugins using which you created user form, you should check with that plugin support if they offer any hook that you should use to hook your custom code.
