See this: https://developer.mozilla.org/en-US/docs/Tools/Debugger

Are you debugging scripts that you wrote? Or random scripts that Firefox reports are problematic? ---- If you see this dialog often, one potential cause is the protected mode feature of the Flash player plugin. That feature has security benefits, but seems to have compatibility issues on some systems. You can disable it by creating or editing a settings file. The following pages/posts provide different approaches for that: * Adobe support article under the heading "Last Resort": [http://forums.adobe.com/message/4468493#TemporaryWorkaround Adobe Forums: How do I troubleshoot Flash Player's protected mode for Firefox?] * Manual steps: https://support.mozilla.org/questions/968190?page=5#answer-509209 * Batch file to automate the manual steps: https://support.mozilla.org/questions/982093#answer-518078 (alternate version of Carm's batch file with a few changes by me: [https://onedrive.live.com/?cid=f7d304d92388737d&id=F7D304D92388737D!336&ithint=file,.bat&authkey=!AP2FXW2Y_3BXZyo]) Flash needs to completely unload from memory (exiting and starting Firefox up again might help) before this takes effect. Any improvement?

There is usually no need to debug the script unless you are its developer and are familiar with the scripts that run on the web page. What page(s) give you this error and what script(s) does this alert mention?

Contact the writers of the program and let them know.