@KrisztinaK Sorry that no one replied to your question. Flash should be installed automatically for Chrome, Chromium, and Firefox. If you saw the animation, it sounds like Flash was in fact installed correctly. There has been a lot of tightening of security by the browser developers around Flash (which has security flaws), so you may have to explicitly enable Flash on the movie site you are trying to visit. Another possibility is that the movie site you are using does not support Linux and is reporting the wrong reason.