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.

Type about:preferences<Enter> in the address bar.

• Cookies; Select Privacy. Under History, select Firefox will Use Custom Settings. Press the button on the right side called Show Cookies. Use the search bar to look for the site. Note; There may be more than one entry. Remove All of them.
• Cache; Select Advanced > Network. Across from Cached Web Content, Press Clear Now.

If there is still a problem, Start Firefox in Safe Mode {web link} A small dialog should appear. Click Start In Safe Mode (not Refresh). While you are in safe mode;

Type about:preferences#advanced<Enter> in the address bar.

Under Advanced, Select General. Look for and turn off Use Hardware Acceleration.

Poke around safe websites. Are there any problems?

Then restart.

Thanks Fred,

I went through this procedure twice, restarting after each, but I'm afraid that the problem still persists.

Thanks Rob

You still had the problem in Firefox Safe Mode?

Remove History For One Site Open the History Manager <Control><Shift> H. In the search bar, enter the name of the site. Right click on one of the listings and select Forget About This Site. This should remove all information, including any passwords / settings.

Apologies to you Fred,

The fault was all of my making. The Windows 10 desktop had been configured in white to aid my visual problems.

This is turn caused the faulty display of Google in Firefox.

A test in the normal Windows theme shows the Google logo and question box frame correctly. Maybe this is why MS don't offer a white desktop as standard in W10.

Sorry and best regards

Rob

Well, now we know.. Please flag your last post as Solved Problem so others will know.

This is probably a good site to be aware of http://www.accessfirefox.org/Firefox_Accessibility_Extensions.php It is a semi-official Mozilla community run site. IIRC the site and many of its add-ons were caught out by Australis. That is probably one site we should reach out to in advance if for instance making anything less distinct smaller, or lower contrast.

Good link, many thanks.