panic: interface conversion: interface {} is []uint8, not *validator.FieldValidator

[maanasasubrahmanyam-sd]

In Plugin.go I am getting error on this function.
panic: interface conversion: interface {} is []uint8, not *validator.FieldValidator
Any suggestion on how to resolve this

func getFieldValidatorIfAny(field *descriptor.FieldDescriptorProto) *validator.FieldValidator {
	if field.Options != nil {
		v, err := proto.GetExtension(field.Options, validator.E_Field)
		if err == nil && v.(*validator.FieldValidator) != nil {
			return (v.(*validator.FieldValidator))
		}
	}
	return nil
}