Firmware Upgrade DDJ RZX 1.09 to 1.10 hangs

While executing the Firmware Upgrade from 1.09 to 1.10 the Progress stops at 10% (second bar) and 0% (first bar). Windows is not frozen but meanwhile almost one hour passed :(

I forgot to mention that I used the german install Option on a Windows 10 OS.

How can I abort the upgrade without damaging the Controller?

Many thanks!