I use the Adobe Flash installed with Ubuntu-Restricted-Extras, in Ubuntu Karmic Koala.

Problem started when I installed the package "Celestia", a 3D astronomy application, but on finding out it wasn't very good and a bit bug-ridden, and uninstalled it. Now I have trouble watching flash videos on YouTube. I just get a black window where the video should play, and nothing.

Please note this does *not* happen on other Flash powered websites, like BBC iPlayer, and all the unwanted Flash-based adverts still play on all other sites! It's just Youtube.

I tried uninstalling Flash, but the Ubuntu Software Centre just gives the option "Upgrade" and "Website", not uninstall. I tried "sudo apt-get remove flashplayer-nonfree" in the shell, but this has had no effect on disabling Flash.

This problem manifests itself in Firefox 3.6.7, Google Chrome 5.0 and Epiphany 2.28, so I guess it must be the Flash Ubuntu add-in, not the individual browsers.

How can I uninstall/reinstall the Flash software so as to cure this problem? I am sure uninstalling Celestia did it, as I have done no other admin things to my system since then, and Youtube flash was working up to that point. Reinstalling Celestia does not cure the problem.

Try uninstalling and reinstalling from Synaptic package manager. Also does it show any error messages?

Hmm - seems I acted too hastily! It's a problem with the Youtube site itself:

http://forums.adobe.com/thread/873994?tstart=0

Apparently, you can get round it by adding an "s" to http:// and this works. Unfortunately, having uninstalled my Flash for Firefox, I cannot now reinstall it as my Ubuntu is too out-of-date, and Synaptic reports that the file for my version is now not available!

However, it appears I only uninstalled the Firefox plug in - everything still works okay in Google Chrome (as long as I put a "s" next to "http" in the address....)

Oh Linux! How could I have ever doubted you..?! I wouldn't like to be a Youtube Admin at the moment! However, if all it takes is adding one extra letter to the URL, it does not seem too much of a problem. Once you know the trick.

Thanks for the input.

OK then but i still don't see how youtube is guilty because i use YouTube a lot and everything just works fine even with Ubuntu (10.10). You should mark thread as solved then and really should upgrade to newer Ubuntu.

Yes, I will be downloading the latest Ubuntu version shortly. Youtube at this time appears to have made a little "fix" and it seems videos clicked on now, automatically stick an "https://" prefix in, so they play. I've still messed up my Firefox though, however this will be fixed when the latest "ubuntu-restricted-extras" is downloaded, when I set up my new Ubuntu.

However, as I say, everything still works in the Google Chrome browser, so it wasn't so much Flash I uninstalled, as Firefox's plugin for it.

But thanks for the assistance.