Firefox shows wrong Silverlight version or "Pipelight Error" although I fixed it / clear plugin cache

Created by Michael Müller
Last updated by:
Sebastian Lackner

For Pipelight >= 0.2.0:

If you are using Silverlight 5.0 and you still see 5.1 as version number in your Firefox plugin list then this is not a bug but a feature :-) Some websites require you to use Silverlight 5.1 although their application would also run with Version 5.0. To get around these check we overwrite the Version number shown to Firefox and the website. Moreover we also change the version number the websites specifies as minimum run time version. You should be able to see the actual Silverlight version in the library path (libpipelight-silverlight5.0) of the plugin.

If something was messed up with your Pipelight installation and you only see "Pipelight Error" as plugin, you need to either follow the instructions for Pipelight < 0.2.0 or execute the following command:

sudo pipelight-plugin --create-mozilla-plugins

to force Firefox to reload the Plugin on the next start. Otherwise you may already have fixed all issues but Firefox will not update the plugin information and you won't be able to use Pipelight.


For Pipelight < 0.2.0:

This bug is not really related to Pipelight but is caused by the fact how Firefox works. Firefox only updates the plugin information when the filedate of the plugin library changes. This works for most plugins as their libraries change on an update, but not for Pipelight. To work around this issue, you need to delete the plugin cache of Firefox so that Firefox is forced to update the plugin details.

Type "about:support" in your address line and hit enter. You should now see a button which opens your profile directory. Click on it and remove the "pluginreg.dat" file in this directory. Restart your browser and check if it works now.