Upgrade to 42.0 on 5 Nov 2015.
Hello, I have upgraded to 42.0 today (5 Nov 2015). I restarted the browser through the add-on "Restart button" because some extensions did not work after upgrading (e.g. ad-block plus...which was no longer visible among add-ons). I had thought that through restarting the browser the add-ons would be working again. However, I cannot open Firefox again. Instead, a pop-up window opens with:
XML Parsing Error: undefined entity Location: chrome://browser/content/browser.xul Line Number 340, Column 5:
<key id="key_toggleMute" key="&toggleMuteCmd.key;" command="cmd_toggleMute" modifiers="control"/>
^
I tried to reinstal the browser through downloading the exe file again, but it is not possible, because Mozila (installed in my C://Program Files (x86) folder) is being recognized by the installation file, and the only option I have is "upgrading" the browser. After upgrading, the browser tries to start but fails, and the above-mentioned pop-up window with "XML...." opens again, leaving me thus stuck in this vicious circle.
This 42.0 upgrade seems to be very problematic in comparison to the previous ones... My OS: Windows 8.1 (updated as well as other software such as Flash...)
Thank you for suggestions. Stanley
Chosen solution
What Firefox locale (user interface language) are you using?
If the above (Safe Mode) didn't identify the problem then do a clean reinstall and delete the Firefox program folder before (re)installing a fresh copy of the current Firefox release. You can try a different locale like en-US if you were previously using a different locale.
- Download the Firefox installer and save the file to the desktop
https://www.mozilla.org/en-US/firefox/all/
If possible uninstall your current Firefox version to cleanup the Windows registry and settings in security software.
- Do NOT remove "personal data" when you uninstall your current Firefox version, because this will remove all profile folders and you lose personal data like bookmarks and passwords including data in profiles created by other Firefox versions.
Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.
- (32 bit Windows) "C:\Program Files\Mozilla Firefox\"
- (64 bit Windows) "C:\Program Files (x86)\Mozilla Firefox\"
- It is important to delete the Firefox program folder to remove all the files and make sure that there are no problems with files that were leftover after uninstalling.
- http://kb.mozillazine.org/Uninstalling_Firefox
Your personal data like bookmarks is stored in the Firefox profile folder, so you won't lose personal data when you uninstall and (re)install or update Firefox, but make sure NOT to remove personal data when you uninstall Firefox as that will remove all Firefox profile folders and you lose your personal data.
If you keep having problems then create a new profile.
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All Replies (3)
hi, this is likely caused by a custom theme or an addon or a custom firefox build. please try starting firefox into safemode by pressing the shift-key while it is launching. while in safemode go to the firefox menu > addons > themes, disable all entries there and try to restart firefox normally. if this didn't work try to disable extensions as well...
Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems
Chosen Solution
What Firefox locale (user interface language) are you using?
If the above (Safe Mode) didn't identify the problem then do a clean reinstall and delete the Firefox program folder before (re)installing a fresh copy of the current Firefox release. You can try a different locale like en-US if you were previously using a different locale.
- Download the Firefox installer and save the file to the desktop
https://www.mozilla.org/en-US/firefox/all/
If possible uninstall your current Firefox version to cleanup the Windows registry and settings in security software.
- Do NOT remove "personal data" when you uninstall your current Firefox version, because this will remove all profile folders and you lose personal data like bookmarks and passwords including data in profiles created by other Firefox versions.
Remove the Firefox program folder before installing that newly downloaded copy of the Firefox installer.
- (32 bit Windows) "C:\Program Files\Mozilla Firefox\"
- (64 bit Windows) "C:\Program Files (x86)\Mozilla Firefox\"
- It is important to delete the Firefox program folder to remove all the files and make sure that there are no problems with files that were leftover after uninstalling.
- http://kb.mozillazine.org/Uninstalling_Firefox
Your personal data like bookmarks is stored in the Firefox profile folder, so you won't lose personal data when you uninstall and (re)install or update Firefox, but make sure NOT to remove personal data when you uninstall Firefox as that will remove all Firefox profile folders and you lose your personal data.
If you keep having problems then create a new profile.
Thanks for your answers. Uninstalling and reinstalling Firefox again helped. My profile has been saved and reused again as you said. Have a nice day : )
Modified by stansen