OS X Flash Installer GUI is empty

I'm trying to update Flash Player on OS X 10.10.1 to 16.0.0.235, so I downloaded the Install Adobe Flash Player application (version 2.0.2.13).

The installation failed.

I then used the Adobe Flash Player Uninstaller to uninstall Flash.

When I now retry the installation, the GUI of the Install Adobe Flash Player application is empty.

The exact sequence is like this:

- I start the Install Adobe Flash Player application

- I am asked for the administrator password

- A window with a black background appears.

- A scroll bar at the top states "Installation wird abgerufen" which is german language for something like "installation is downloaded".

- after a couple of seconds the scroll bar disappears and the window GUI remains empty

- this does not seem to change any more (I've waited for hours to see if something would happen).

I've tried several times, even after having rebooted the computer, but I always get the empty GUI.

I am not sure how to recover from this or how to install Flash at all, now that I've removed the previous version.