Chrome driver hangs when using user data

Question

The browser opens but the debugger hangs. If I comment out the AddArgument line then it proceeds fine. Any ideas?

   var chromeOptions = new ChromeOptions();
    chromeOptions.AddArgument("--user-data-dir=C:\\Users\\Ian\\AppData\\Local\\Google\\Chrome\\User Data");

    IWebDriver driver = new ChromeDriver("C:\\Users\\Ian\\Desktop", chromeOptions);

Answer 1

It seems to want all other Chrome windows closed to work with existing user data.