Pressing Play does nothing

I just purchased Minecraft Dungeons for Windows to run in a PC with Windows 7. When I press Play in the Launcher nothing happens. The "c:\Program Files (x86)\Minecraft Dungeons Launcher\debug.log" file is empty. I can see from the Task Monitor that the following processes are running: Dungeons-Win64-Shipping.exe, Dungeons.exe and MinecraftDungeonsLauncher.exe. The after clicking the "Play" button gets disabled but no other window is shown. If I end the process "Dungeons.exe" from the task manager, I get the message "Game crashed" on the launcher window.

Any ideas?