Problems with AR Vuforia and android!?

I've been trying to get Unity running on Android for days with Vuforia :-(
Unfortunately without success...
The following happens:
The app launches (Unity logo comes up)
Then there is only a black screen ...
Locally on a Windows 10 computer, it works without problems via WebCam!

I want the app to start, the camera on and I can capture images with the camera ...
As I said in Windows, it works without problems.

I tried the following versions:
1804.4.xx
2019.1.xx

Has anyone got to work?
And if so, what versions of Unity / Vuforia and all under Windows, so I get it running on android ...

Thank you for your help

Bernd

 

Hi. Be sure that u have set correct API key to the ARCamera game object (in vuforia configuration). If u got it and still no background in camera then possibly u have no grants to camera, open application settings in your android and find your app. Then set system grants to camera and file system(optional).

 

I got a developer key from Vuforia.
I have entered this.
As far as I know there is no other key?
The app is allowed to access the camera and files (allowed)

 

Which Unity and Vuforia versions work with the camera under android?

 

hi i sometimes have this problem and it made me very disappointed for a week that i couldnt fix it i asked sb and he said maybe my file has crashes that ive done unpurpose i started a new project and tested a cube it worked fine and i started the project from the beginning and it worked