Ridiculously, when I three-figer tap on some words, OS X built-in function is to look up this word in dictionary. Even these characters are in a mess, OS X can still read words and look it up. It's funny.

So I changed the font settings, still no work.

Yes, opera://settings/fonts does exist on OSX.

I think it's a new bug just for 10.11 GM, since Apple changed some fonts in this update.

I found someone in Opera Desktop blog having same issue too. Also Opera Developer installed on 10.11 GM.

Hope Opera will fix this soon, and I even cannot send a bug report with these messy characters.

Hi sgunhouse, thanks for reply.

This is definitely not a language, I believe. My OS X language is set English(US), and I live in China now.

I tried Opera and Opera Beta, both work well, but when it comes to Opera Developer, everything went wrong.
I have add English in my Opera Developer, but no work. On Windows, it's easy to change Opera UI language in this section, but on OS X, there is no option for that, just

Change the default spell check dictionary or add new dictionaries
Dictionaries... (a button)
Specify your preferred languages for webpages
Preferred languages... (another button)

So I can't change UI language. I reinstall Opera Developer, and still have this problem. As Opera and Opera Beta do not have such issue, maybe a bug?

Why can't I see my comment here?

Thanks, sgunhouse!

I have installed Opera, Opera Beta and Opera Developer on my OS X 10.11 GM. Opera and Opera Beta both work fine, with English UI and preferences. So it's a problem of Opera Developer.

As Opera determines its language by system language on OS X, not like it on Windows which you can choose manually, there seems no way changing that.

My system language is English and I live in China now. Does Opera Developer have new way setting its language? Additionally, all menus such as File, View, Edit, etc are pretty fine, but all pages such as Preferences, Start Page, etc are wrong. So I think it's something about encoding, because these pages are just special web pages.

Just installed Opera Developer 33.0 on my Mac with 10.11 GM.

When I opened 33.0, almost every page in 33.0 went wrong. My system language is English, but it looks like:

This is Preference page. What's wrong?