New Version 5.15.3 does not start

I just tried to open WinSCP.
The attached windows appears, and in German it says below
"Please donate to activate automatic updates"
Both buttons "Update" and "Close" do not work.
The window closes automatically after a few seconds.

Thanks for your report.
I have sent you an email with a debug version of WinSCP to the address you have used to register on this forum.