Swagger crashing on my api prototype.

[Erik Pepping]

Hi,

i'm using asp.net core for my Web-api's.
I have swagger installed and configured. Everything works fin until I add the following prototype:

    [HttpPost]
        public IActionResult Addall([FromBody] List<Account_group> items)
        {
           
            if (items == null)
            {
                return BadRequest();
            }
            account_groupRepository.Addall(items);
            return Content("Converted");

        }

The trick is the list.
Chaging it to Account_group[] items
does not work either.

Any help would be apriciated.