In looking at your screenshot, I'm able to see all of the roads in both images and neither screenshot looks any different from what I can see when I visit the same location in Google Maps in my installation of Firefox as well as Google Chrome.

Are you able to look at the screenshots on a different computer to see if you have the same issue seeing the lines? It kind of sounds like maybe the contrast settings on your monitor/screen are too low, which is making it difficult to see the small colour difference between the white roads and the light grey background.

Additionally, are you able to check how the Google Maps page appears in another browser like Safari or Google Chrome? This would help determine if the issue is Firefox-specific or if it happens system wide.

Thank you, but there seem to be communication problems.

On the Mozilla support page, I wrote a full reply to your useful message, then attached an image (8 MB jpg from my mobile phone) to the reply. The web page appeared distorted, with the reply box shifted up and overlapping the headings. The page hung with the image failing to upload and the only way to retrieve the situation was to use the back arrow, which lost both your message and the reply.

PS the initial problem may be connected to a Win10 update.

An 8MB image may be too large for this forum. Try running the image through this image compression service to see if it can shrunk to a more reasonable size.

Thank you The photo (reduced in size) has a moire pattern but no minor roads.

I have tried to follow online advice about changing the contrast, colours etc, but the Win10 dialog boxes appear to have been changed. Can you suggest a link to decent advice?

I've attached a screenshot from my system of the same location <strike>at roughly the same scale</strike> (I guess I'm a little more zoomed in on the map, but it should still work) as the image that you included in your post. If you view the screenshot in Firefox, are you able to see the smaller roads between B5074, A51, A530 and Wellington Road?

Also, please try saving the image to your computer by using this Firefox Send download link (it's valid for 7 days). Then, open it using something other than Firefox (Microsoft Paint, the default image viewer, etc). Can you see the small roads then?

I'm just trying to see if the issue is with how Google Maps is actually displaying the roads or if it's just a colour issue on your computer or monitor. This is why I attached an image from my system because I can see the small roads.

If you can't see the roads in Firefox or another program, you may want to change your monitor's colour settings to increase the brightness and/or the contrast settings. The steps to do this will depend heavily on the monitor that you are using, so you may need to consult your user manual or do an online search to find steps for your specific monitor.