I feel desperate! Ever since I upgraded to Ubuntu 10.04 my SWF mostly will not work!
A workaround that used to always work, and now sometimes works: I would go to synaptic package manager, install SWF 10.1, then install the SWF 10.1 installer. This would un-install my first installation, but leave my installer installed! I do not understand this, but SWF usually would (after restarting firefox) begin working, until my next startup of the computer, that is! I have to fix it every logon, and sometimes more often.
I also get different results from three sources of test data. "Applications/Ubuntu Software Center" shows I have SWF 10.1 installed. "Synaptic Pkg Manger" also shows I have SWF 10.1, but when I run the Mozilla plugin check, it thinks I have SWF 9.0r48.
When I press the "outdated version" button on the mozilla plugin check page, I go through a routine to update the plugin, but this check page still thinks I have SWF 9.0r48, and none of my flash items like utube work. BTW, I did try to install SWF 10.1, both the APT version, and the tar.gz version to no avail.
The videos never develop, I see a cartoon that looks like a lego toy with a frown face and the words "The Adobe Flash Plugin has Crashed".