It means that you have to add multiple validators in array

. Example:

With Error

profileFormGroup = {
  budget: [null, Validators.required, Validators.min(1)]
};

Above one throws error that validator to return Promise or Observable

Fix:

profileFormGroup = {
  budget: [null, [Validators.required, Validators.min(1)]]
};

Explanation:

In angular Reactive form validation done…