Q:

Not allowing me to show ads because of errors in the console

A few days ago my ads in my game were working perfectly then suddenly out of nowhere they stopped working.  I think it has something to do with unity not importing the ads extension into my game.  I tried turning off the built in extension and getting the sdk from the asset store manually the errors went away but the ads would not show up.  I don't know whats wrong I have everything set up my build settings is set to android and my ads are turned on I don't know why it's behaving like this
Here is my code:
using System. Collections;
using System. Collections. Generic;
using UnityEngine;
using UnityEngine. Advertisements;

public class Ads : Money {

  void Update()
    {
        Advertisement. Initialize("1424659");
    }

    public void ShowRewardedAd()
    {
        if (Advertisement. IsReady("rewardedVideo"))
        {
            var options = new ShowOptions { resultCallback = HandleShowResult };
            Advertisement. Show("rewardedVideo", options);
        }
    }

    private void HandleShowResult(ShowResult result)
    {
        switch (result)
        {
            case ShowResult. Finished:
                money = money + 90;
                PlayerPrefs. GetInt("money", money);
                PlayerPrefs. SetInt("money", money);
                Debug. Log("The ad was successfully shown."); 
                break;
            case ShowResult. Skipped:
                Debug. Log("The ad was skipped before reaching the end."); 
                break;
            case ShowResult. Failed:
                Debug. LogError("The ad failed to be shown."); 
                break;
        }
    }
}

As you can see I basically copied this from the unity code samples section and modified it a little to fit my needs. 
Here are the errors:

Assets/Ads.cs(4,19): error CS0234: The type or namespace name Advertisements' does not exist in the namespaceUnityEngine'.  Are you missing an assembly reference? 
Assets/Ads.cs(24,35): error CS0246: The type or namespace name `ShowResult' could not be found.  Are you missing an assembly reference? 

A:

Let's take a look at the first error message:

Assets/Ads.cs(4,19): error CS0234: The type or namespace name Advertisements' does not exist in the namespace UnityEngine'.  Are you missing an assembly reference? 

The compiler is saying that it can't find UnityEngine. Advertisements.  This means you don't have ads enabled.  To enable ads, as of Unity 5.2, you should use the Unity Service Window and not the Asset Store package.  Before you can use Unity Services, you need to get a Unity Services Project ID.  
From the Unity documentation for Unity Services:

To get started with Unity’s family of services, you must first link
  your project to a Unity Services Project ID.  
[...] 
Go to Window > Unity Services, or click the cloud button in the toolbar. 
[...]
Select your organization and click Create. 

Your project now has a special ID it can use to talk to Unity servers and ask for advertisements.  Now you can enable Unity Ads.  
From the documentation for Unity Ads:

Open the Ads configuration window from Window > Services > Ads. 
Click the switch on the right-hand side to turn Ads on, then answer a few questions about the game you are making. 

At this point, the compiler should stop showing errors, and your code should run just fine.