Hello Basti,

The manual installation of the apk file is not possible at our client where I had to make the installation on Tuesday, due to general company policy, it's only allowed to install software from the Google play store.
I am not allowed to copy the software on the smartphone with a usb cable and also send the apk via e-mail and then install it from there is also not allowed. The security on the smartphone blocks all these options.

Best regards,

Dirk-Jan