Hello Jin_VE,
Can you be more specific about what kind of comment and what ASCII characters you’re using? What sort of error do you receive? I’ve been able to compile in 4.17 with Kanji characters in comments in C++ code without a problem, if that is the type of comment you’re speaking of. Also, please create an Answerhub post about this issue in the Bug Reports section with the information I requested so we can more easily track the issue and provide support. Feel free to leave a link to the Answerhub post here whenever you make it.