After reporting Rafael about Windows 10 build 9926 issues with x64 edition, he sent me another build on 1st March 2015 with some installation fixes as well. I was busy during that time so sorry for little delay. You should be able to use UxStyle on Windows 10 build 9926 x64 now.
Changelog in version 14.2
-Updated UxStyle for Windows 10 to version 0.2.4.2 fixing Windows 10 build 9926 compatibility with x64
Download: UXTheme Multi-Patcher 14.2
If you have any issue related to UxStyle, please file an issue to UxStyle’s GitHub.