Icons disappear from launcher after install apps

Hi,
I would like to use a Sony Xperia X with SFOS 4.4. But unfortunately at firstboot the installation of SailFish apps are not really successful. The apps are installed, but the icons disappear from the launcher immediately after installation, so I cannot start them. I tried to install other application and to remove then install the installed apps from the Jolla store, but the situation is the same. After the end of the installation the launcher icon disappers.
And the fingerprint reader is not working at all, so I have to type the PIN always that is not too convenient.

Thanks for your hints and help in advance.