Why does the application crash on the second call to DownloadStringTaskAsync?

Question

.NET

Hello. The application is thrown into an UnhandledException on the second call to this function.

public static class Locator
    {
        public static async Task<List<Location>> GetCitiesAsync(string token = "", int max = 5)
        {
            WebClient wc = new WebClient();
            string resultContent = await wc.DownloadStringTaskAsync(new Uri(string.Format("http://www.site.ru/ajax/geo.cshtml?_=r&context=&token={0}&max_matches={1}&use_similar=0", HttpUtility.UrlEncode(token), max.ToString())));
            // parse ...

            Locations ll = JsonConvert.DeserializeObject<Locations>(resultContent);

            return (from l in ll.locations select l).Take(max).ToList();
        }
    }

calling like this

async void LocationsFunc(string search)
        {
            if (IsLoading)
                return;

            IsLoading = true;
            List<Location> locs = await Locator.GetCitiesAsync(search);
            IsLoading = false;
}

A first chance exception of type 'System.Exception' occurred in System.Windows.dll
A first chance exception of type 'MS.Internal.WrappedException' occurred in System.Windows.dll
A first chance exception of type 'MS.Internal.WrappedException' occurred in System.Windows.dll
A first chance exception of type 'MS.Internal.WrappedException' occurred in System.Windows.dll

try/catch does not help, wherever it is.
I don't know, what's the matter? What difference does it make to him? After all, a new WebClient instance is being created.
In the callback/event style, everything works.

Answer 1

And even that doesn't work?

if (IsLoading)
            return;
try {
            IsLoading = true;
            List<Location> locs = await Locator.GetCitiesAsync(search);
} catch (Exception ex) {
            Debug.Break();
            // тут бы MessageBox какой-нибудь или записать в лог
} finally {
            IsLoading = false;
}

Answer 2

It's very strange, but now the code from my initial post is working.. yesterday I fixed it by replacing the line
List locs = await Locator.GetCitiesAsync(search);
on
foreach (Location loc in await Locator.GetCitiesAsync(search))
...
and it worked. Apparently the whole point was to bind the Task to some local variable. try/catch wrapped everything and everything, but nothing was caught, but just fell .. I didn’t try to restart the emulator, maybe it was somewhere in the depths of the system ..