Unity ads crash my iOS app when trying to show it

Error Message :

Code (CSharp):

1.  

Initialization Code called in CreateUI:

Code (CSharp):

1. [UnityAds initialize:unityAppID delegate:self];

Delegats Code:

Code (CSharp):

1. - (void)unityAdsReady:(NSString *)placementId
2.  
3. {
4.  
5.     unityAdsReady = TRUE;
6.  
7.     NSLog(@"unityRewardVideo:unityAdsReady: Video ready to be displayed PlacementID: %@", placementId);
8.  
9. }
10.  
11.  
12. -(void)unityAdsDidError:(UnityAdsError)error withMessage:(NSString *)message
13.  
14. {
15.  
16.     NSLog(@"unityRewardVideo:unityAdsDidError: %@", message);
17.  
18.     UnitySendMessage("RewardVideoManager", "UnityAdsVideoCompleted", "false");
19.  
20. }
21.  
22.  
23. -(void)unityAdsDidStart:(NSString *)placementId
24.  
25. {
26.  
27.     NSLog(@"unityRewardVideo:unityAdsDidStart: Video started PlacementID: %@", placementId);
28.  
29. }
30.  
31.  
32. -(void)unityAdsDidFinish:(NSString *)placementId withFinishState:(UnityAdsFinishState)state
33.  
34. {
35.  
36.     if (state != kUnityAdsFinishStateSkipped) {
37.  
38.         UnitySendMessage("RewardVideoManager", "UnityAdsVideoCompleted", "true");
39.  
40.         NSLog(@"unityRewardVideo:unityAdsDidFinish: Video compleated PlacementID: %@", placementId);
41.  
42.     }
43.  
44.     else
45.  
46.     {
47.  
48.         UnitySendMessage("RewardVideoManager", "UnityAdsVideoCompleted", "false");
49.  
50.         NSLog(@"unityRewardVideo:unityAdsDidFinish: Video skipped PlacementID: %@", placementId);
51.  
52.     }
53.  
54. }

Code used to show the video :

Code (CSharp):

1. - (void) showUnityVideoAd
2.  
3. {
4.  
5.     NSLog(@"Show Unity Reward Video");
6.  
7.     if (unityAdsReady)
8.  
9.     {
10.  
11.         NSLog(@"Showing Unity Reward Video");
12.  
13.         [UnityAds show:thisClass];
14.  
15.     }
16.  
17.     else
18.  
19.     {
20.  
21.         NSLog(@"Not Ready Unity Reward Video");
22.  
23.         [self ShowVideo:mad:"" CurrentProviderVideo:-1];
24.  
25.     }
26.  
27. }

Xcode whose build using Unity 5.4.1f1
Xcode version 7.2.1
UnityAds version 2.1.0

 

Thanks for the replay the class whose set up perfectly, the fix whose changing
this
[UnityAds show:thisClass];
to this
[UnityAds show:[thisClass topMostController]];