Test Studio 2017.1 / Freeze when calling custom code

using System.Text;
using System.Threading.Tasks;

namespace Common
{
    public class Utility
    {
        public static void StartCustomApp(Manager manager, ExecutionContext executionContext, string customAppPath, string args = "", int waitForWindow = 10000, int waitingTime = 10000)
        {
            Assert.IsNotNull(manager, $"Manager is null.");

            manager.ActiveApplication.MainWindow.Window.Minimize();
            manager.ActiveApplication.Detach(false);
            var executablePath = executionContext.DeploymentDirectory + customAppPath;

            Assert.IsTrue(File.Exists(executablePath), $"Can not found {customAppPath} path.");

            var appName = Path.GetFileNameWithoutExtension(customAppPath);

            // Prepare the process to run
            ProcessStartInfo app = new ProcessStartInfo();
            app.Arguments = args;
            app.FileName = executablePath;        

            Assert.IsNotNull(manager.LaunchNewApplication(app), $"Failed to connect to {appName}.");

            manager.ActiveApplication.WaitForWindow($"~{appName}", waitForWindow);

            System.Threading.Thread.Sleep(waitingTime);

            manager.ActiveApplication.MainWindow.SetWindowFocus();
            manager.ActiveApplication.MainWindow.Window.Maximize();
            manager.ActiveApplication.MainWindow.RefreshVisualTrees();
        }

        public static void connectToApp(Manager manager, string appName, bool closeAppOnDetach = false)
        {
            manager.Log.WriteLine(DateTime.Now.ToString()+" - Start connectToApp"+appName);
            Assert.IsNotNull(manager, $"Manager is null.");

            Assert.IsNotNull(manager.ActiveApplication, $"ActiveApplication is null.");

            manager.Log.WriteLine(DateTime.Now.ToString() + " - detach previous App");
            manager.ActiveApplication.Detach(closeAppOnDetach);

            var proc = Process.GetProcesses().Where(p => p.ProcessName.Contains(appName)).FirstOrDefault();

            Assert.IsNotNull(proc, $"{appName} is not running.");

            manager.Log.WriteLine(DateTime.Now.ToString() + " - connect to App " + appName);
            Assert.IsNotNull(manager.ConnectToApplication(proc), $"Failed to connect to {appName}.");

            manager.ActiveApplication.MainWindow.Window.SetFocus();
            manager.ActiveApplication.MainWindow.Window.SetActive();
            manager.ActiveApplication.MainWindow.Window.Maximize();
            manager.ActiveApplication.MainWindow.RefreshVisualTrees();
        }

        public static void CloseApp(string appName)
        {
            var runningApp = System.Diagnostics.Process.GetProcesses().Where(p => p.ProcessName.Contains(appName));
            string executablePath = string.Empty;

            if (runningApp.Count() > 0)
            {
                foreach (var process in runningApp)
                    process.Kill();
            }
        }
    }
}