<Add-on> could not be installed because Firefox cannot modify the necessary file.
I see that for the issue:
<Add-on> could not be installed because Firefox cannot modify the necessary file.
The usual fixes include: - ensuring that xpinstall.enabled is set to true - ensuring that extensions.alwaysUnpack is set to true
What might be the non-usual fixes as I have set both to true and I still get the message above.
I have tried installing the <add-on> after I have set the values to true, then again after restarting my browser, then again after restarting my computer and finally tried creating a new profile and repeated each of the steps after setting the 2 preferences to true.
Additional System Details
Installed Plug-ins
- The QuickTime Plugin allows you to view a wide variety of multimedia content in Web pages. For more information, visit the QuickTime Web site.
- Google Update
- Next Generation Java Plug-in 1.6.0_35 for Mozilla browsers
- NPRuntime Script Plug-in Library for Java(TM) Deploy
- Shockwave Flash 11.3 r300
- Adobe Shockwave for Director Netscape plug-in, version 11.6.5.635
- RealJukebox Netscape Plugin
- RealPlayer(tm) LiveConnect-Enabled Plug-In
- 6.0.12.1863
- 5.1.10411.0
- Adobe PDF Plug-In For Firefox and Netscape 10.1.1
- Citrix Receiver Plugin (Win32)
- DRM Store Netscape Plugin
- Npdsplay dll
- DRM Netscape Network Object
- Windows Presentation Foundation (WPF) plug-in for Mozilla browsers
- np-mswmp
- Office Plugin for Netscape Navigator
- Tool bar for Image Web Server Images
- Progress bar for Image Web Server Images
- The ECW plugin allows you to view gigabyte size imagery over the internet. Visit http://www.ermapper.com for more information.
- Macromedia Authorware Web Player Netscape plug-in, version 6.5 F1
- Streaming 3D Viewer version 2.1 {#2100}
- PLATINUM technology, inc. Plug-in for viewing 3D worlds authored in VRML
Application
- User Agent: Mozilla/5.0 (Windows NT 5.1; rv:10.0.3) Gecko/20100101 Firefox/10.0.3
More Information
Windows XP and Firefox 10 (I cannot upgrade my browser to a new version)
Can you at least update to the latest Firefox 10.0.10 ESR version?
Firefox 10.0.x ESR:
So a new profile with no other extensions didn't work as well?
- https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
- http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues
Which extension is causing this problem or can't you install any extensions at all?