A plugin is a piece of software that displays internet content that Firefox is not designed to display. These usually include video, audio, online games and presentations that are made in patented formats. Plugins are created and distributed by the companies that make those patented formats. Some common plugins are Adobe Flash, Apple QuickTime, and Microsoft Silverlight.
A crash happens when a piece of software abruptly stops working. Plugins sometimes crash for various reasons, and cause Firefox to crash along with it. For more information about Firefox crashes, see Firefox crashes - Troubleshoot, prevent and get help fixing crashes. Some plugins load separately from Firefox, allowing Firefox to stay open if the plugin crashes.
Crash reports only include technical information to help Firefox developers determine what went wrong, and how to fix it. These reports do not include personal information. The information sent in a report includes:
Many problems with plugins can be solved by updating to the latest version of the plugin. To check if any of your installed plugins are out of date, visit Mozilla's Plugin Check & Updates page.
The name of the plugin that crashed can be found in the error message.
Breakpoints can trigger Firefox's hang protection. You can disable hang protection by setting dom.ipc.plugins.timeoutSecs to -1. See the Mozilla Developer Network documentation for details.