title: Async-Await func return throws a System.FormatExceprion
body: <p>I've been using these lines of code to get Currency from site and when I return value it throws a System.FormatExceprion (curr != null on return)</p>
  <pre><code>        public static async Task&lt;double&gt; GetCurrencyVal(string url)
          {
              string xPath = &quot;//*[@id=\&quot;__next\&quot;]/div[2]/div[2]/section/div[2]/div/main/form/div[2]/div[1]/p[2]/text()[1]&quot;;
              var config = Configuration.Default.WithDefaultLoader();
              var doc = await BrowsingContext.New(config).OpenAsync(url).ConfigureAwait(continueOnCapturedContext: false);
              await doc.WaitForReadyAsync().ConfigureAwait(continueOnCapturedContext: false);
              var curr = doc.DocumentElement.SelectSingleNode(xPath);
              if (curr != null)
                  return double.Parse(curr.Text().Trim());
              else
                  Console.WriteLine(&quot;Error&quot;);
              return -1;
          }
  
          private void TimerOnTick(object sender = null, EventArgs eventArgs = null)
          {
              var now = DateTime.Now.AddSeconds(-DateTime.Now.Second);
              double usd = GetCurrencyVal(someUrl).GetAwaiter().GetResult();
              double eur = GetCurrencyVal(someUrl).GetAwaiter().GetResult();
          }
  </code></pre>
  <p>this line throws a System.FormatException</p>
  <pre><code>double usd = GetCurrencyVal(someUrl).GetAwaiter().GetResult();
  </code></pre>