Dear Developers,

We have a project with Unity4.6.3 and Vuforia 3-0-7 cloud based application. Now we are going to upgrade the project with Unity5.1.1f1 and Vuforia 4-2-3.

Our application has multiple tracker images on cloud. Once tracker image detected, its relavent data will download from our own web-server and displayed on tracker.

I have created a new Unity5.1.1f1 project and imported vuforia-video4-2-3 package.

When am integrating... facing some issues. 

i have imported CloudRecoEventHandler and content manager scripts from old project.

On Start, we are getting clould access key and secretkeys from web-services. once access key received, we are enabled the CloudRecoEventHandler.cs script.This gives an error "Null Referense" at  mObjectTracker.TargetFinder.ClearTrackables(false); .

    public void OnStateChanged(bool scanning)
    {
        if (scanning)
        {
            // clear all known trackables
            mObjectTracker.TargetFinder.ClearTrackables(false);

         }
 

    }

If i comment the above 

 mObjectTracker.TargetFinder.ClearTrackables(false); line, something working. Most of the times augmentation is not working.

If i delete the ARCamera and again if i add, Augmentation is working. Is there any problem with Vuforia4-2-3 and Unity5.1.1f1 ?

We are very urgent to upgrade the project but we are facing these type of problems and getting struct.

Please help, how to resolve the null referense issue at  mObjectTracker.TargetFinder.ClearTrackables(false); .

and ARCamera issue ?