> 
> Error CS1061 'Task>' does not contain a definition for
>  'FirstOrDefault' and no extension method 'FirstOrDefault' accepting a
>  first argument of type 'Task>' could be found (are you
>  missing a using directive or an assembly reference?) ,
> 
> 
> 

making a web application with facebook controller, included using system.linq but still getting the error for `FirstOrDefault()`.
I dont know what the problem is, i reinstalled visual studio too as he same thing works for my friends laptop.
I juggled around to see if the method is present in the library and it is there but still not getting past this [Image for the same](https://i.stack.imgur.com/x9s7p.jpg) 

```
public async Task<ActionResult> Posts()
{
    var currentClaims = UserManager.GetClaimsAsync(HttpContext.Identity.GetUserId());

    // Error occurs here at FirstOrDefault
    var accesstoken = currentClaims.FirstOrDefault(x = > x.Type == "urn:tokens:facebook");

    if (accesstoken == null)
    ...
}

```