Hi , while trying to add new user into one of the created group so it is showing :- "An error has occurred while handling the request." error message, but it was very normal activity to add any user into group. thanks
This is a very generic error message.
Check your error logs in the modeler to see more details about what type of error has occured.
Check the error log in your modeler or application log, and there you can find out what the issue could be.
Looks ike security settings, such as not having the rights to add records to an entity.