Make sure you are not blocking content.

Start Firefox in Safe Mode {web link} by holding down the <Shift> (Mac=Options) key, and then starting Firefox.

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

One issue that seems more common lately is Firefox's Tracking Protection feature. When it is blocking content in a page, a shield icon will appear at the left end of the address bar next to the padlock icon. This article has more info on managing this feature: Tracking Protection {web link}

Thank you for your reply I did try safe mode when the problem was first noticed after I searched Mozilla support and saw similar issues to which safe mode action was an initial start to diagnosis. I also disabled Kaspersky protection . Since the problem first came to light this morning I now can tell you that if I leave Firefox for a couple of hours it will display the login page, but only at the first attempt, subsequentially the fault reappears. When I try to log in again the URL is correct and the login page remains blank. There is no tracking shield at the address bar The information icon tells me I am on a secure site with no tracking attempts If I go via the Home Page on the Barclays website to the login I get the same result. Microsoft Explorer does work so I am not completely stumped. It is strange that this has occured after a long track record of reliability from Mozilla Thanks for the information Regards TW

60012334 said

Thank you for your reply if I leave Firefox for a couple of hours it will display the login page

Many secured sites will logout any connection that is idle.

but only at the first attempt, subsequentially the fault reappears

Many site issues can be caused by corrupt cookies or cache.

• Clear the Cache and
• Remove Cookies

Warning ! ! This will log you out of sites you're logged in to. You may also lose any settings for that website.

• Cookies; Delete cookies to remove the information websites have stored on your computer {web link}

• Cache; How to clear the Firefox cache {web link}

If there is still a problem, Start Firefox in Safe Mode {web link} by holding down the <Shift> (Mac=Options) key, and then starting Firefox.

A small dialog should appear. Click Start In Safe Mode (not Refresh). Did this help?

While you are in safe mode;

Try disabling graphics hardware acceleration in Firefox. Since this feature was added to Firefox it has gradually improved but there are still a few glitches.

How to disable Hardware Acceleration {web link}

You should also note, while you think nothing is changed on your system, the system, and most programs, get updates from time to time.

Sometimes one of those updates becomes a problem.