@YGYL
I've verify it and You've right!
I've test with ~15 languages and appear this happen only with CN.
One possible solution is to use TW when You need this plugin.
I've see some differences between this files (LengthUnit_zh_CN.properties and LengthUnit_zh_TW.properties) and after some minor modifications appear to work.
Anyway I suspect an translation error on SH3D rather than a plugin error.