Unity Ads not initializing in Android (3.5.0)

hi,

I tried setting up an ad project today and used the latest SDK (3.5.0). However after following all the implementation steps on the website, I am still unable to initialize the UnityAds object.

Earlier, a few months ago, I had tried and was able to load ads before in my other app. But then, I had used

UnityAds.initialize(Activity, ID, testmode)

Now it asks for Context.. i.e
UnityAds.initialize(Context,ID, testmode)

(I have tried this.GetContext, this.getApplicationContext.. etc)...

Unity Ads not initializing in Android (3.5.0)