Exception: '

I have a Blazor Webassembly project with a controller method as follows:

[HttpGet]    public async Task<List<string>> GetStatesForProfile()    {        IConfigurationSection statesSection = configuration.GetSection("SiteSettings:States");        var sections = statesSection.GetChildren();        var states = statesSection.GetChildren().Select(s => s.Key).ToList<string>();        return states;                }

The razor page calls this method:

private async Task<bool> GetStatesModel(){    try    {        States = await http.GetJsonAsync<List<string>>("api/account/getstatesforprofile");                    ...    }    catch (Exception ex)    {        Console.WriteLine($"Exception: {ex.Message}, Inner: {ex.InnerException.Message}");    }

I get this Exception:

Exception: '<' is an invalid start of a value.

I read these values from appsettings.json file, And there is no '<' in values.

{      "SiteSettings": {    "States": {"New York": ["NYC"],"California": ["Los Angeles", "San Francisco"]    } }

Also I put a breakpoint in the controller method and it doesn't hit.What is this error? Is it from parsing json? and how to resolve this?