Microsoft has announced the new Fall Creators Update of Windows 10 some days ago (version 1709).
This new version includes some new design elements on the Desktop devices, called the "Fluent design", which I have now included to Friendica Mobile, too. It has now an acrylic Background in the navigation area and light effects when hovering over buttons and other elements. To get the new design effects you can update your Windows 10 Desktop to the new Fall Creators Update manually (or wait for the automatic update rollout).
I have decided to stop supporting older Windows 10 Version previous to the Creators Update (Version 1703). You can still use Friendica Mobile on older Windows 10 versions, but they will not get any new functions or updates in the future.