Oh and I also get the banner "You must login to this network before you can access the internet"!

Let’s do a full clean re-install;

Note: Firefox comes in three or more folders on all computers. They are;

Maintenance: (Programs Folder) <Windows Only> Firefox itself: (Programs Folder) And two folders in the profile of each user on the computer for each Firefox profile for that user.

If you remove the Firefox folder, the user profiles would not be affected.

Download Firefox For All languages And Systems {web link}

Save the file. Then Close Firefox.

Using your file browser, open the Programs Folder on your computer.

Windows: C:\Program Files C:\Program Files (x86) Note: Check Both Folders

Mac: Open the "Applications" folder. https://support.mozilla.org/en-US/kb/how-download-and-install-firefox-mac

Linux: Check your user manual. If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it. See Install Firefox on Linux; https://support.mozilla.org/en-US/kb/install-firefox-linux

If you downloaded and installed the binary package from the Firefox download page, simply remove the folder Firefox in your home directory. http://www.mozilla.org/firefox#desktop ++++++++++++++++++++++++++++ Look for, and remove any Mozilla or Firefox program folders. Do not remove the Mozilla Thunderbird folder if there is one.

Do Not remove any profile folders.

After rebooting the computer, run a registry scanner if you have one. Then run the installer. +++++++++++++++++++++++++++ If there is a problem, start your Computer in safe mode and try again.

http://encyclopedia2.thefreedictionary.com/Linux+Safe+Mode This shows how to Start all Computers in Safe Mode; Free Online Encyclopedia

I have tried that and it makes no difference. Clean uninstall, registry cleaned and the exact same issue on reinstall - first run generates the 0xc0000022 error and then second run opens Firefox but its just a shell - nothing loads - options won’t load - cannot do about:config and it is asking me to login to the network despite it being on my private LAN at home.

Could you check this next:

Compatibility Mode Problem in Firefox 73

Could you double-check that your regular installation of 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?

None of these options are set so no impact on the issue which remains.

Thanks

Thank you for checking that.

Does your system have software called 0patch? This is their support article:

https://0patch.zendesk.com/hc/en-us/articles/360011227079-Mozilla-Firefox-73-can-crash-upon-launching-when-0patch-Agent-is-installed

There may be other security software that tries to hook into browser processes and isn't compatible with Firefox 73, but support volunteers don't have a comprehensive list of the ones confirmed to create a problem.

I don’t have 0patch and oddly firefox was working yesterday.

Start your Computer in safe mode with network support. Then start Firefox. Try Secure websites. Is the problem still there?

http://encyclopedia2.thefreedictionary.com/Linux+Safe+Mode Starting Any Computer In Safe Mode; Free Online Encyclopedia

Tried safe mode and the same result :(

Try clicking on Help->Troubleshooting Information and see if this particular page will load.

Mid clicked this is not solved

Did you check the Windows Event log to see if there is more detail available ?

Nothing in the event viewer aside form the 0xc0000022 from the first run and none of the help pages load.

CNCC said

Try clicking on Help->Troubleshooting Information and see if this particular page will load.

I have the same issue as OP when I came into work this morning. Troubleshooting Information loads for me. Is there something I should be looking for here?

nthpixel said

CNCC said

Try clicking on Help->Troubleshooting Information and see if this particular page will load.

I have the same issue as OP when I came into work this morning. Troubleshooting Information loads for me. Is there something I should be looking for here?

Yes, this is what happens with my Firefox in Windows Normal Mode. Have you tried to see if Firefox runs normally if you boot Windows in Safe Mode?