In bittorrent sync version 1.4.75 and 1.4.83 any file names containing Korean characters will not sync. The log files on both machines indicate that the files are skipped due to an "invalid UTF8 file name". This problem did not exist with version 1.3.109. The problem seems to be unique to Korean characters. I've tried both Chinese and Japanese and files with these characters synchronize properly. System Information: Gentoo Linux Kernel Version 3.14.14 File System: ext4 cat sync.log |grep -i version version: 1.4.83 The relevant section of the sync.log file is shown below. [20140918 2