Some of my friends can’t see Myanmar font on OS X 10.11 El Captain. If they use pseudo-Unicode font called Zawgyi, they’ll face similar problem whenever they upgrade their OSs.
It’s time to move on and use built-in Myanmar fonts which follow Unicode standards.
If you still want to read Zawgyi texts, you may install one of the following browser extensions/add-ons for your favourite browsers.
It’s called MUA Web Unicode converter and developed by San Lin Naing from Myanmar Unicode Area. You Rock!
If you disabled built-in Myanmar fonts, hope you didn’t, please enable from FontBook.
And please remember there are browser extensions so you can install on Windows or Linux too.