My copy of Windows 10 Pro updated to v1903 yesterday and the Cryptomator UI (v1.4.10-x64) has been unusable ever since. The UI pops up with a completely blank (white) window with no buttons or text, just a title bar: 
I am unable to access any of my vaults. I can’t seem to find any parameters I can add to the startup icon to automate the mounting of a volume. Does anyone have any suggestions as to how I should proceed?
Ehhh, actually not. I found an issue on our bug tracker which sounds similar, but the person who reported it had at least some boxes: https://github.com/cryptomator/cryptomator/issues/824
After trying multiple solutions, I stumbled across these articles about JavaX Apps and Windows10 on certain hardware combinations (all of which had to do with blank windows being displayed on JavaX apps with hardware acceleration enabled):
https://stackoverflow.com/questions/51493508/javafx-label-text-not-showing
https://www.reddit.com/r/javahelp/comments/84w6i6/problem_displaying_anything_with_javafx_only/
I simply added “-Dprism.order=sw” (without quotes) as the first line of the [JVMOptions] section of the Cryptomator.cfg file in the app subfolder. This turns off the hardware acceleration.
The window is back to normal again. I hope this helps someone else.
Same issue on GitHub: