Usually the Hotfix extension is a temporary quick fix and the change is put into the next release of Firefox, so I suspect that the problem wasn't caused by disabling the Hotfix extension. More likely a coincidence.

Is there a public page demonstrating the menu problem or is a login needed to view it? If you could give a link that would be helpful.

And also more generally:

When you have a problem with one particular site that previously worked normally, a good "first thing to try" is clearing your Firefox cache and deleting your saved cookies for the site.

(1) Clear Firefox's Cache

See: How to clear the Firefox cache

If you have a large hard drive, this might take a few minutes. If you do not see the number going down on the page, you can reload it using Ctrl+r to check progress.

(2) Remove the site's cookies (save any pending work first). While viewing a page on the site, try either:

• right-click (on Mac Ctrl+click) a blank area of the page and choose View Page Info > Security > "View Cookies"
• (menu bar) Tools > Page Info > Security > "View Cookies"
• click the padlock or "i" icon in the address bar, then the ">" button, then More Information, and finally the "View Cookies" button

In the dialog that opens, the current site should be pre-filled in the search box at the top of the dialog so you can remove that site's cookies individually.

Then try reloading the page. Does that help?

If that doesn't help, could you test in Firefox's Safe Mode? In Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is not running: Hold down the Shift key when starting Firefox.

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement? (More info: Diagnose Firefox issues using Troubleshoot Mode)

Thanks for the reply.

The site is behind a Login Page and Firefox worked perfectly the day before yesterday. The upgrade occured and the message appeared saying Hotfix was not compatible with 48.0.2 and was disabled.

I've tried clearing cache and history.

I've also started in safe mode which had no effect on the problem.

Chrome works as does Edge (neither are my favourite). I may have to copy all my Bookmarks over and use one of them until the problem is fixed in a future release.

Could you look up what version you were using before the update. Usually you can find it this way, either:

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, look for a "Show Update History" button. This should list each recent update so you can see what your immediately previous version was.

In order for this to get diagnosed and fixed, someone will need to provide access to the application. Do you have any contact information for that government office, or a link to the agency's main page?

Hi.

Thanks for the help. The update history only lists this one: Firefox 48.0.2 (20160823121617) Security Update Installed on: Thursday, September 1, 2016 8:14:12 AM Status: The update was successfully installed

It doesn't list the previous version.

This is a government website with finance access so extremely unlikely I can provide any contact details that will give you access. I'll just have to use Chrome or Edge for now.

Thanks anyway.