Please check if all your plugins are up-to-date. To do this, go to the Plugin Check site.
Once you're there, the site will check if all your plugins have the latest versions.
If you see plugins in the list that have a yellow Update button or a red Update now button, please update these immediately.
To do so, please click each yellow or red button. Then you should see a site that allows you to download the latest version. Double-click the downloaded file to start the installation and follow the steps mentioned in the installation procedure.
Note: If your version of a plugin is newer then the one shown by the test page, do not worry about it. This just means the plugin you have is a recent update.
If the updater shows Unknown, this plugin is not on the testers list. To check that plugin, go to the home web site of the owner of that program.