Diễn đàn hỗ trợ Firefox

Hello,

I install language pack from https://addons.mozilla.org/en-US/firefox/language-tools/ https://addons.mozilla.org/en-US/firefox/addon/russian-ru-language-pack/

But there is still no sub-menu item in the menu

Sometimes when I go to click on songs on YouTube it doesn't show the whole bottom part of the video's screen. It has some of it but does not show the fullscreen mode option to click on. When i open up Chrome it's fine. I'm using the newest update of Firefox.

For the past week, when I sign into Facebook, the news feed is constantly refreshing itself. Once in a while the first post will stay, but the remainder of the news feed keeps refreshing. It is impossible to read anything as posts flash on and off, mostly off. The news feed is the only thing that is affected, visiting pages for likes and groups load and display properly, as do the games I play. The same occurs if in the private window mode. This does not happen if in the Chrome browser. What can be done to correct this situation?

I'm not very good at English, so I use a translator. After updating to the latest version of Firefox, the problem I'm having is that when I play a YouTube video on the web side, the playback box will have a large white colour, as shown in the red box below. I would like to know what is causing this, my current version is 123.0