After install language add on cannot checkout w Paypal

[webrookie 0]

H1,I have recently installed the addon for two kinds of Chinese. I have a language box with the flags of the countries inside, so the visitor can switch between Chinese and Engish as they go from pages to pages. Everything is fine but when a visitor tries to add an item to the cart or when he/she tries to check out in the Chinese interface the screen would freeze and just leave a white screen there. The checkout in my English interface if completely fine, it is only in Chinese that I am encountering this problem. Please help me as my shop is live and I have been trying to fix this for the last few days with no improvement. I have tried to compare the files one by one and so far they all seems to be identical. Thank you.