I don't know what you did, but i can easily change that by changing the default action for PDF files in preferences -> Applications. I've been using PDF.js mys

I don't know what you did, but i can easily change that by changing the default action for PDF files in preferences -> Applications. I've been using PDF.js myself for i think a year now (Used to install it directly from their Github page), and it's a great reader if you aren't an heavy PDF user. I barely have to open a PDF, and when i do it's usually just text and images, not any fancy stuff. And i guess most computer users are just like me. If you open PDFs all day, and are a power user, i guess that nothing can replace a good standalone reader. It's still kinda slow, but it has done some incredible progresses in the year i've been using it. And i'm sure it will just get better and better.