Installed Mavericks right after it was released. I've been watching a lot of YouTube on my ATV and iPad. Today I went to check some things out while on my MBP and YouTube is not functional. It says I need to install the latest Flash Player. Have I not watched a video on my laptop since installing Mavericks? Hmm. Maybe not. Alright. Installed Flash Player. You Tube is not aware. Tried uninstalling, re-installing Adobe. No help. Some videos play, most report "Missing Plug-in", and "Install latest Flash Player". Stupendous. Anyone else seeing this, or have a solution?