I recently changed some things on my firefox browser. One thing I changed was that the font using the Theme Font and Size Changer. I have since disabled that. I also changed the theme of firefox, and I disabled that as well. And I started using Tab Groups and added several pinned tabs. One of those pinned tabs was for YouTube, although when I tried to use the tab, I noticed that I couldn't view the entire video--it was cut off. I've closed all the pinned tabs and I'm not even using the tab groups anymore. Now, I still can't view youtube videos. I'm not sure if it's every flash video--I'm not sure how to go about searching the net for just flash videos. But I've disable all the pinned tabs. Restarted firefox, restarted my computer, tried changing the zoom, and I tried to uncheck the box for "Enable Hardware Acceleration" but I can't. I've definitely tried different videos and can't get any to work right. I can actually view the video, but only part of it. It plays, but it's cut off. I'm not really sure where to go from here. Also, I'm working on a Mac. Thanks for your help. Sherrie