I found my problem. It was a corrupt History file in Chrome.
I noticed the Clear Browsing Data (under More Tools) was not able to get a total for the "Browsing History" section.
Then from the Google Chrome Help Forum (Syd Hutchinson) I found this procedure:
Firstly make sure Chrome is switched off. Go into task manager and make
double sure there are no instances of it running. If it has been open it
is sometimes easier to close it and then reboot your machine to ensure
it is closed. Now open file manager and go to C:\Users\*your
id*\AppData\Local\Google\Chrome\User Data\Default. Replace *your id*
with your user id. Now look for a file named History and delete it. Just
that one file. If it was like mine it will probably be a large file.
Mine was 500Mb. Close file manager and open Chrome and all should be ok.
A new History file will be created and it will now be just a few kbs.
Deleting the one file "History" fixed the problem! Such a relief!