Mobile-app integration fails

Hi,

I noticed that the sensors of phone did not update anymore in HA.
I could not find what was wrong so I uninstalled the mobile_app integration.
Maybe a re install would fix the problem.
Now I’m trying to re install it I get this message:

Afgebroken

Open de mobiele app om de integratie met de Home Assistant op te zetten. Zie de docs voor een lijst met compatibele apps.

It is Dutch and means that the installation is aborted/broken off and that I have to check the documentation and I did.

It says to check that my config contains mobile-app and it does, it did work before and I did not changed it.

default_config:
mobile_app:
discovery:

How can I trace this so I can find the problem?
Or does someone knows what is going wrong?