I installed this beta version in Brazilian Portuguese Windows 8.1, and a Issue has been found:
-> After initialization of the Avast resident modules, when the user tries to open a program or system functionality that requires Permission Elevation (UAC - User Access Control), the Windows CONSENT.EXE crashes with Address Violation, and Error Report opens. If you disable the Resident modules, the windows operates normally. Once happened an event that froze my system, and I couldn't even open task manager, needing to reboot system manually.