Translation of opensurvey could not be used in Chinese (Taiwan)

Hi

I have translated all opensurvey of Chinese (Taiwan) .
But when i go to poll page , all words are still in english .
So i try to download from transifex and replace the oringinal file , that still don’t work .
Then i try to edit opensurvey.lang directly , still not work .
Are there anyone knows how to fix it ?

Note: i think this issue also happen in early version .