Are Libre Office versions 4.2.6 and 4.3.0 completely compatible with Windows 8.1, 64 bit ? No clear answer found so far.
Note that the Windows build of LO is 32bit, so if Java is required, a 32bit Java install will be needed, even under the 64bit version of Windows. Also note bug fdo#77061.
• Bug 71690 - TDF Site: Download → System Requirements: Add Windows Server 2008 R2, 2012 and Windows 8.1, + FreeBSD
• LO Website ML: add more OS version to system requirements page
• AskLibO: Does LibreOffice run on Windows 8.1, Windows Server 2008 R2 and Windows Server 2012?