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firefox provides an error message when starting

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After doing an auto upgrade to Rel 73, firefox started but no windows would load., I uninstalled firefox and went to the Mozilla site and did a re-install. After the reinstall when I click on finish to start the program I get the following

firefox.exe - Application Error. The application was unable to start correctly (oxc0000005)
After doing an auto upgrade to Rel 73, firefox started but no windows would load., I uninstalled firefox and went to the Mozilla site and did a re-install. After the reinstall when I click on finish to start the program I get the following firefox.exe - Application Error. The application was unable to start correctly (oxc0000005)

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Yes, yes, yes. I've been trying to fix this issue for 2 weeks now. Took me this long to find this link. Now how does the run in compatability mode for w7 get checked? I've been using edge and it's a disaster.

Thanks, thanks, thanks. Dave

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All Replies (9)

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hello, at https://old.reddit.com/r/firefox/comments/f2d5cu/nothing_will_load/ affected users said a similar problem was caused with custom exploit protection rules for firefox under windows 10 or running the browser in compatibility mode for windows 7...

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Could not find 0patch in the registry.

When I click on Start and open the program menu, I seethe Firefox icon. I click on that and Firefox does start but it doe not load any pages. Microsoft Edge is working OK.

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Hi doowopper70, could you double-check that Firefox is not set to run in backwards compatibility mode? Here's how:

Find the icon you use to start Firefox, and either:

  • Right-click a desktop shortcut, then click Properties
  • Right-click a Firefox icon pinned to the Taskbar then right-click Mozilla Firefox, then click Properties

You should clear all the boxes on the Compatibility tab for best results (giant screenshot below).

Any difference the next time you start Firefox?

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firefox is running now but I cannot restore my bookmarks the file is large but after the restore the bookmarks are all empty

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Clearing all the check boxes on the Compatibility tab of the shortcut used to launch Firefox Release 73 resolved the problem for me. Thanks, jscher2000.

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doowopper70 said

firefox is running now but I cannot restore my bookmarks the file is large but after the restore the bookmarks are all empty

What kind of file do you have? Is it one of the automatic backups from an older bookmarkbackups folder, for example with 1,234 bookmarks and folders:

bookmarks-2020-02-10_1234_gibberish==.jsonlz4

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Chosen Solution

Yes, yes, yes. I've been trying to fix this issue for 2 weeks now. Took me this long to find this link. Now how does the run in compatability mode for w7 get checked? I've been using edge and it's a disaster.

Thanks, thanks, thanks. Dave

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DogT said

Now how does the run in compatability mode for w7 get checked?

Hi Dave, usually it requires you to let Windows repair a problem, but perhaps there are other ways.