Whenever I run a search using Google all the items recovered in the search appear within white text boxes. This makes genuine search items difficult to distinguish from sponsored pages and advertisements. Similarly if I run a Google Scholar search the first thing that comes up is a series of similar boxes for individual scientists that link to their CV-type pages, which is not at all what I asked for. Other links on the GS searches do not show up as previously giving the number of cached items and also where these items might be downloaded.

I thought initially this was caused by some add-on or similar that I had accidentally switched on but I can find nothing of the kind. None of my colleagues are suffering the same inconvenience. I have tried uninstalling and reinstalling Firefox but it will not go away. What can I do to eliminate the boxes, please?