Hello? I don't want to see random black squares, so I turned off "hardware acceleration". https://support.mozilla.org/en-US/questions/1079934 But, I found some bugs after I re-started Firefox 49.0.1 1. Underscore _ is not appearing on the Naver login page. https://nid.naver.com/nidlogin.login?url=http%3A%2F%2Fmail.naver.com%2F See the first screenshot. I want to see "underscore" and have "hardware acceleration" turned off. Please tell me the solution. :) 2. All text is in bold on the Namuwiki page. http://bit.ly/2dMbjIB Look at the second screenshot. Only some words should be in bold. I want to see the Namuwiki page with "hardware acceleration" turned off. Please tell me the solution. Thank you very much for your help.