The latest Tor Browser update seems to have disabled streaming video using Adobe flash, resulting in the message "Media not supported on browser. Error code: source media support." The same happened when I updated Tor on a second computer. Is this a glitch in the updated Tor browser? Is there a way I can return to the previous version?
Tor browser bundle does not use flash in the browser bundle, it seems to me that you previously had it installed manually (which is not recommended), then the updater naturally overwrites those settings.
Flash is insecure and is not included in the tor browser bundle.
Flash is a plugin that requires the separate binary executable container to run it, and this fact - regardless of the old NSAPI and other issues - is a big problem and leak source. Unless you're using an isolated and fully-routed VM - you should disable all plugins of such kind, not just Adobe Flash