Character set problems

The original doc file contains chinese character.
While trying to convert the .doc file into a .pdf file, I encountered the character set problem.
You can see from the attachment.
How can I solve this problem?

Hello

Thanks for your inquiry. Could you please attach your input document here for testing? I will check the problem on my side and provide you more information.

Best regards,

ok, here’s another smaller document. The same character problem occurs.
thanks.

Hello

Thanks for additional information. Please make sure that SimSun font is installed on the PC where you perform conversion to PDF. If not, please try to install SimSun font. This should fix the problem. Please let me know in case of any issues.
Best regards,