[9.000-8] Reinstall of endpoint protection fails

Hi,
got a very strange problem:

Few days ago a uninstalled the EP from a client.
Yesterday i tried to reinstall, but both installers (thin, thick) showed an error.
The thin client tried to configure the AutoUpdate - it took several minutes and after installation i got the message "computer needs to be connected to internet".

Thick-Installer installs the EP but Update failes, update-Configuration is emty.

OK i thought, let´s try it out at another PC:

Same Problem;
installed EP -> online in UTM
uninstalled EP and tried to reinstall: Same error as above.....

Kind regards

Sebastian