Why is UNDO CLOSED TAB disabled by default?
Whenever my browser is updated, the UNDO CLOSED TAB is disabled by default. At that time, I need to go to about:config to enable them.
Additional System Details
- Adobe PDF Plug-In For Firefox and Netscape 11.0.06
- Version 126.96.36.199
- Google Update
- NPRuntime Script Plug-in Library for Java(TM) Deploy
- Next Generation Java Plug-in 11.20.2 for Mozilla browsers
- The plug-in allows you to open and edit files using Microsoft Office applications
- Office Authorization plug-in for NPAPI browsers
- Nokia Suite Enabler Plugin
- Picasa plugin
- The QuickTime Plugin allows you to view a wide variety of multimedia content in Web pages. For more information, visit the QuickTime Web site.
- Shockwave Flash 15.0 r0
- iTunes Detector Plug-in
- User Agent: Mozilla/5.0 (Windows NT 6.1; rv:34.0) Gecko/20100101 Firefox/34.0
Please see the article How to fix preferences that won't save.
You may have a user.js file setting that preference each time you start up Firefox. Information on how to remove it is in the article above, or more specifically this section:
If you have no user'js file, the article shows other possible reasons why the preference keeps getting reset.