A patch from Dukian (actually done by hand was easier, got an UTF8 issue) There are many different i18n file naming approaches for language.country couple. For Traditional Chinese ... OFBiz uses java way: zh_TW, datepicker uses zh-TW, and el-rte needs this patch. It uses actually zh_tw, see the full version line 1108: Dukian will file this issue to el-rte project too.